The First Fifty Years of Acta Stomatologica Croatica (1966 - 2016): Citation Analysis.

Acta Stomatologica Croatica (ASCRO) citation analysis was made on the occasion of fifty years of publishing the journal (1966 to 2016). The aim of the study was to determine the impact of the changes that have been occurring over the last ten years on the visibility and citation of ASCRO by comparing the obtained results with the 2008 ASCRO citation analysis. Materials and
Methods: The sample was obtained by searching the Web of Science Core Collection database, and the data were processed by descriptive statistics.
Results: A total of 1,618 papers were published in ASCRO in which 477 papers were cited in 903 citations. Each published paper was cited on average 0.6 times, while each of the cited papers received 1.9 quotations on average. The largest number of citations per paper is 20, and the largest number of citations per year is 63 in 1991. According to age, 96 papers received the largest number of citations three years after they had been published, and the oldest cited papers are 45 years old. ASCRO was cited in 302 journals, and the largest number of citations (19%) was recorded in Collegium Antropologicum. Out of the total of 903 citations, 41% were made by Croatian authors. Croatian and foreign authors cited in 3.7% of papers, and in 55.3% of papers citations were made only by foreign authors. ASCRO is cited by authors from 73 countries, of which 33 are European, 19 are Asian, 10 American, 9 African and 2 authors come from Australia and Oceania.
Conclusion: ASCRO's improvement in the quality has been recorded in all of the analyzed parameters over the past ten years with respect to the results obtained by citation analysis in 2008.

Introduction

The journal's fifty years of continuous publishing is a respectable occasion for a retrospective review of the growth and development of the journal. In 1966, the journal Acta Stomatologica Croatica (hereinafter: ASCRO) was initiated by the Society of Croatian Dental Health Workers, the Dental Section of the Croatian Medical Association and the School of Dental Medicine of the University of Zagreb. It publishes four issues per year in one volume, and the only exception is Volume 7 published in 1972/73. At the beginning, only the papers that were of interest to dentists as well as to dental technicians and nurses were published. The papers were provided with summaries in Croatian, English and German (no longer being used over time), and they contained references. By 1987, they were written in Croatian only when the first papers appeared in English. A significant change occurred in 1998 since when all the papers have been written bilingually, that is, in Croatian and English. This practice has been retained to date and certainly contributes to the development of Croatian professional terminology. It also provides uninterrupted communication with the world scientific community. All papers are subject to double blind review by domestic and foreign reviewers.

The next major step in the development of the journal was made in 2006 when the parallel publication of printed and online versions started (). The publisher then decided to give access to the full text of the work freely and free of charge to all interested experts, scientists and the general public.

Hrcak: a portal of the Croatian scientific journals - Since 2006, ASCRO has been part of Hrcak, a portal that brings together Croatian scientific and professional journals that offer open access to their scientific papers (). In the first stage, 8 journal years (2000; 34 - 2007; 41) were published by the press in pdf format on the Hrčak portal. Current numbers are published immediately after the release of the printed version of the journal. Hrčak Portal offered outstanding technical and informational support to the editorial staff, hence the idea of digitalization of older years was rapidly emerging. For its implementation, a team of associates was assembled, none of whom was skilled for this job and preparations were made. The digitization was done in three years (2011 - 2014), covering the thirty and three years of the journal (1966; 1 - 1999, 33) (). In this way, the complete ASCRO has become globally available since 2014.

DOAJ (Directory of Open Access Journals) is a multidisciplinary database that indexes more than 12,000 scientific and professional electronic journals available in open access. ASCRO has been involved in the DOJ base since 2007. The full text of the article was available through the link to Hrcak until 2017 when the editorial board starts submitting articles in XML format with all metadata. By storing metadata, articles are searchable through DOAJ. In the same year, in 2017, ASCRO successfully passed the reevaluation process.

EBSCO - Dentistry & Oral Sciences Source - EBSCO is an American aggregator offering information services for the academic and research community. In 2008, ASCRO's Editorial Board signed an Inclusion Contract in a specialized database of Dentistry & Oral Sciences Source. The base is only available to subscribers.

Scopus - is Elsevier index citation database presented in 2004. In 2009, after completing the quality review process, ASCRO was included in the indexed journal corpus.

CrossRef DOI (Digital Object Identifier) - The Editorial Board has registered ASCRO in the International DOI Foundation and all articles that have been published since 2015 have been assigned a DOI tag (from issue 3). In this way, the users of ASCRO are additionally facilitated access to the full text of the article.

CrossRef Similarity Check - one of the Crossref Foundation services that helps journal editors check the content of the received handwriting before submitting it to the review. Thus, since 2015, the possibility of publishing articles with unreliable data and research has been significantly reduced, but it has not been completely eliminated.

PMC (PubMed Central) - a biomedical journal database with a secured access to full text articles opened the "door" of ASCRO in May 2016. The evaluation process lasted for three years mainly due to problems with fine-tuning the XML format of the bibliographic record. Inclusion in the database was only possible when all the track elements were fully compatible. By browsing the PubMed bibliographic database, articles published in ASCRO from 2014 have been available.

Creative Commons License - Introduced in 2017, and the Editorial Board of the offered options has opted for the level of the Creative Commons Attribution-Noncommercial-NoDerivates 4.0 International License. This license allows everyone to download articles and share with others if they provide the source bibliographic data. The articles that are used f or commercial purposes must not be modified without the written permission of the proprietor.

ESCI (Emerging Sources Citation Index) is an integral part of the Web of Science Core Collection, and since 2018 ASCRO has been included in the index database. This is why the Editorial Board received recognition for its work and encouragement to raise the quality threshold when evaluating the received manuscripts.

The aim of the study was to determine the impact of changes which the Editorial Board have incorporated into ASCRO for the past ten years thus affecting its visibility and citation. Since there is a citation analysis of ASCRO from 2008, a comparison of results has been made where possible and appropriate ().

Material and Methods

This paper deals with 50 volumes / years of the ASCRO journal in which 1,618 papers were published. Searching for the WoS Core Collection database was done in March 2018 for the range of 1966 to 2016. Since ASCRO was not indexed in WoS bases in the analyzed period, a citation data analysis could not be obtained using Basic Search. The search was done in Cited Reference Search by the Cited Work field. This means that the search involved only citations from ASCRO papers if they had been published in a journal which was indexed in WoS databases. The citations from all other journals were lost for the analysis. In addition, the name of the journal in non-indexed journals was not standardized. It has been noted in the form stated by the author of the cited paper. Numerous variants of the name of the same journal have been found.

In the effort to collect as complete results as possible, in setting up an information query, a right shortcut was used, and the search criterion was act * sto * c *. Due to the use of the right skid, apart from the ASCRO citations, we have received a smaller number of other publications that have been manually removed. The search results were stored in Excel program. First, the deduplication of the same records was made in such a fashion that the papers were preceded by columns Author, followed by Column Title, and then by column Year. In this way, bibliographic records of the same papers that were stated in different ways were found. Citations of the same paper were summed up and associated with the most complete bibliographic description of the paper.

The bibliographic data of the cited papers were collected in such a way that each individual record was manually transferred to the MS Excel table. Statistical data processing was done using the method of descriptive statistics.

Results

In the analyzed period, 1,618 papers were published, which averaged to an annual rate of 32.4 .The database was searched by the name of the journal, and the Act * sto * c * graphs were employed using the right skid, for the most complete coverage of the papers. The search resulted in 642 papers. 561 papers from ASCRO were found by extracting papers referring to other publications. Subsequently, the deduplication was performed and 477 papers were taken to make the sample for the analysis. For the analyzed papers, 903 citations were recorded. Out of the total of 1,618 papers, each paper was cited on average 0.6 times. Out of the total of 477 cited papers, each paper received 1.9 citations on average.

Analysis of the cited papers

The analysis of the number of citations per paper: The number of citations ranges from 1 to a maximum of 20 citations per paper. Table 1 shows the distribution of papers by number of citations. Since most of the papers were expected, i.e. 286 received one citation (60%). Subsequently, the number of papers with two citations suddenly dropped to 96 papers (20.1%), followed by 49 papers with three citations (10.3%). Only 45 of the remaining papers received four or more citations.

Table 1

Number of countries and continents on which the authors of the citing papers live

broj radova = number of articles	286	96	49	17	11	7	3	1	2	2	1	1
broj citata = number of citations	1	2	3	4	5	6	7	8	9	10	14	20
%	60,0	20,1	10,3	3,6	2,3	1,5	0,6	0,2	0,4	0,4	0,2	0,2

Figure 1 shows the number of published papers and the number of citations per year. The range of papers is from a minimum of 16 papers published in 1980 to a maximum of 43 papers published in 1997. Between 30 and 40 papers have been published per year in the period of thirty-five years, which is clearly the optimum number in this publishing concept. From 1966 to 2016, 32 papers on average were published per year.

Figure 1

Number of papers and citations per year

Analysis of number of citations per year: The range of citations per year was from 0 to 63 citations. No citation was recorded for papers published in 1976 and 1980, and papers from 1991 received a maximum of 63 citations. When analyzing the number of citations per year, three periods can be observed. Papers published in the first sixteen years (1966 - 1981) received on average only 2.4 citations per year. In the following sixteen years (1982 - 1997), the published papers received on average 16.5 citations per year, while in the last eighteen years (1998 - 2016), 33 citations per year were averaged, Figure 1.

Analysis of citations by age: The age range of the cited papers is from 0 to 45 years. In the 0 year, 23 papers were cited. Subsequently, the number of cited papers which were 1 year old is 49 and those which were two years old are 56. The most frequently cited papers were those which were 3 years old (96), followed by 79 papers that were six years old. In the following period of time, the number of cited papers is almost regularly falling by age of up to sixteen year old papers. The papers older than sixteen years are rarely cited, Figure 2.

Figure 2

Division of citations regarding the age of the paper

Analysis of the citing papers

Analysis of journals with the citing papers: The papers published in ASCRO are cited in a total of 302 journals. The analysis revealed that the largest number (168) of citations was recorded in the Collegium Antropologicum journal, representing 19% of the total number of citations. The next issue of Acta Clinica Croatica shows a sharp drop, that is, 33 citations (3.7%). Subsequently, the number of citations fell slightly, and the number of journals in which the citations were recorded rose slightly. One citation was registered in 174 different journals, Table 2.

Table 2

Number of citations per journal

broj citata = number of citations	168	33	31	22	14	12	10	8	7	6	5	4	3	2	1
broj časopisa = number of journals	1	1	1	1	2	1	6	3	5	7	9	11	25	55	174

Analysis of co-authorship of the citing papers: Out of a total of 903 citations, ASCRO was cited only by Croatian authors in 370 papers (41%), by Croatian and international co-authors in 33 papers (3.7%), and 500 papers (55.3%) were cited only by international authors. Table 3 shows comparative co-operation data from previous () and current research.

Table 3

Co-authorship of the citing papers

Suautori = coauthors	2007.		2016.
	broj radova	%	broj radova	%
hrvatski = croatian	196	76,3	370	41
strani = foreign	54	21	500	55,3
hrvatski i strani = croatian and foreign	7	2,7	33	3,7

Author country analysis: For the purpose of the analysis of the countries from which the authors of the citing works come from, the data were collected from a detailed bibliographic description according to the author's affiliation field. When several co-authors from one state appeared in one paper, the country was registered only once. The papers published in ASCRO were cited by authors from 73 countries. As expected, the majority of authors who cited ASCRO are from Croatia (411 papers), followed by authors from India in 72 papers, those from the United States in 69 papers, those from Serbia in 37 papers. In 34 papers, ASCRO was cited by authors from Brazil and the United Kingdom; in 29 papers by authors from Turkey; in 25 papers ASCRO was cited by authors from Italy; in 23 papers ASCRO was cited by authors from China; in 18 papers, it was cited by authors from Germany; in 16 papers ASCRO was cited by authors from Australia and Saudi Arabia; in 15 papers it was cited by Iranian authors; in 14 papers by authors from Bosnia and Herzegovina; in 13 papers by authors from Poland. In 11 papers ASCRO was cited by authors from Egypt, France and Japan; in 10 papers by authors from Malaysia and Spain; in 9 papers by authors from Denmark, Macedonia, Romania, Slovenia and Taiwan; in 8 papers by authors from Greece, Kosovo and the Netherlands; in 7 papers by authors from Portugal;, in 6 papers by authors from Ireland and Thailand; in 4 papers by authors from Austria, South Korea, Sweden, Switzerland and the United Arab Emirates; in 3 papers by authors from Belgium, Czech Republic, Chile, Finland, Jordan, Slovakia; in 2 papers by authors from Argentina, Bangladesh, Bulgaria, Montenegro, Indonesia, Yemen, South Africa, Costa Rica, Mexico, Nigeria, Norway, New Zealand and Pakistan, and in 1 paper ASCRO was cited by authors from Botswana, Ethiopia, Ghana, Israel, Qatar, Kenya, Kuwait, Hungary, Malta, Morocco, Peru, Russia, Syria, Tanzania, Ukraine and Venezuela.

We aimed to get a global image of ASCRO communicability by classifying the countries from which the authors of the citing papers come and by stating the continents on which they live. Thus, the analysis showed that the authors from 33 European countries cited ASCRO in 709 papers, followed by citations by authors from 19 Asian countries in 185 papers, the authors from 10 US states in 134 papers, the authors from 9 African countries in 21 papers, and authors from 2 states in Australia and Oceania in 18 papers. Table 4 provides comparative data from previous () and current research on the number of countries classified by continents on which the authors of the citing papers live.

Table 4

Number of countries according to the continents from which the authors come

Kontinent, Continent	Broj država 2007.Number of countries in in 2007	Broj država 2016. Number of countries in 2016
Afrika, Africa	1	9
Amerika, America	4	10
Azija, Asia	7	19
Australija i Oceanija, Australia and Oceania	2	2
Europa, Europe	15	33
Ukupno država = Total countries:	29	73

Discussion

The study has shown that a total of 1,618 papers were published in ASCRO from 1966 to 2016. Out of the total number of papers, 477 (29.5%) were cited, with a total of 903 citations. Based on this, it was found that each cited paper received an average rate of 1.9 citations, while the average number of citations for all published papers was 0.6. If we compare these results with the results of the 2007 survey (), we can see that 185 papers were cited out of a total of 1,273 published papers. Thus, the 2007 survey shows that 14.5% of papers are cited, and in 2016 the percentage of cited papers has increased to 29.5. The average number of citations for the cited papers rose from 1.4 to 1.9, while the average number of citations for all published papers increased from 0.2 to 0.6. The recorded increases are not negligible since they have been created over the last ten years in which ASCRO journal has been coming out.

Cited papers

Analysis of the number of citations per paper: We can see from Table 1 that the range of citations is from 1 to 20 citations per paper. One citation was recorded for 286 papers (60%), while one paper received 20 citations, which is the largest number of citations. The 2007 survey showed that 75.1% of the cited papers received 1 citation, while the largest number of citations per paper was 5. There was a noticeable drop from 75.1% to 60% in the share of papers with one recorded citation as well as an increase from 5 to 20 citations in the maximum number of citations that some paper received.

Analysis of number of citations by years: It shows that no citations were recorded for the papers published in 1976 and 1980, and the papers from 1991obtained the largest number of citations (63). Comparing these data with the 2007 survey we can see that in the meantime some papers from 1969 and 1977 have been cited and the number of years with zero citations has been reduced from 4 to 2 years. Over the same period, the maximum number of citations per year increased from 28 to 63 citations for the papers from 1991.

Analysis of citations by age: The age range of the cited papers is from 0 to 45 years. In the 0 year of publication of the paper, 23 papers were cited. The papers that are three years old received the largest number of citations (96). They are followed by the papers which are six years old with 79 citations. The number of citations of older papers is gradually falling to sixteen, and the papers which are older than sixteen years are rarely cited. A comparison with the data from the previous survey shows that the number of citations in the year has risen from 8 to 23. Three years old papers received the maximum number of citations in both surveys, with an increase from 24 to 96 citations.

In 2007, the oldest cited paper was 34 years of old, and in 2016, the oldest cited paper was 45 years old. We believe that publishing the online version of the journal since 2006 and digitizing the journal from the first issue (completed in 2014) has maximized the visibility and availability of all published articles. This could have influenced the citation of very old papers that were hardly available to the world scientific community in the past.

Citing papers

Analysis of journals with citing papers: The papers published in ASCRO were cited in a total of 302 journals. The largest number of citations that is 168, citations (19%) was recorded in Collegium Antropologicum. The journal shows a drop in 33 citations and continues to 1 citation recorded in 174 different journals.

A comparison of these results with the results of previous studies shows that the number of journals in which the ASCRO journal was cited has risen from 65 to 302. In both studies, the largest number of citations was recorded in Collegium Antropologicum, but their share in the total number of citations dropped from 44.7% to 19%. This can be considered a positive shift as well as a significant increase in the number of journals in which ASCRO was cited as it points to the true internationalization of the journal.

Analysis of the co-authorship of citing papers: Out of a total of 903 citations, ASCRO was cited only by Croatian authors in 41% of papers. ASCRO was cited by Croatian and international authors in 3.7% of papers, while ASCRO was cited only by international authors in 55.3% of papers. If we compare these results with the results of previous research we can see that the share of citations by only Croatian authors fell from 76.3% to 41%, while the share of citations by international authors increased from 21% to 55.3%. This also points to the positive trend towards the internalization of ASCRO. The share of co-authorship citations by Croatian and international authors has increased slightly from 2.7% to 3.7%. An intensification of co-operation between domestic and foreign scientists could result in new research ideas.

Analysis of authors by countries: The papers published in ASCRO were cited by authors from 73 countries. As can be expected, ASCRO was most cited by authors from Croatia (411 papers), while ASCRO was cited only once by authors from 16 countries.. The division of countries by continents has shown a significant increase in the number of states for all continents except Australia and Oceania (Table 4) ().

If we compare this data with the results of previous research, we can see that the number of countries from which the authors of citing papers have risen from has increased from 29 to 73. Thus, in the last ten years, for the first time, ASCRO has been cited by researchers from 44 countries.

In both research, papers published in ASCRO are most cited by scientists from European countries, and the number of the countries has increased from 29 to 33. It is followed by an increase in the number of researchers from Asian countries from 7 to 19. The number of researchers from US states has increased from 4 to 10 countries, whereas from African countries an increase is from 1 to 9. The unchanged number of authors has remained in 2 states in Australia and Oceania.

ASCRO is visible and accessible in the farthest corner of our planet, as the above mentioned numbers confirm. We believe that without the full access to full texts, a good deal of potential readers would not have the opportunity to read the articles published in ASCRO.

Conclusions

Our research has pointed to positive changes that have been occurring in all analyzed parameters over the last ten years. This is encouraging, but efforts on raising the quality of the journal need to be made in order to further improve the quality of the journal. This task can be accomplished only by publishing quality papers.

The visibility of ASCRO has been increased by inclusion of the journal in the world index base. This is also an indirect quality assurance because the journal had to undergo a quality assessment process for each individual base.

If we want to sort out the changes that have had a significant impact on the positive indicators, these would be the three Editorial decisions: publishing the online version of the magazine, digitizing the whole collection from the first year of publishing and making the full texts completely free to all potential readers.

In 2015, the Editorial decision was made on the Similarity Check, which was carried out using the iThenticate program. This decision will have a major impact on the future of ASCRO. This program facilitates the recognition of manuscripts that contain plagiarized data. A consistent appropriation and rejection of such manuscripts will raise the standard for accepting the manuscript. This opens the door to further progress in dynamics of the journal.