Authors: K Sommerfelt; H W Andersson; K Sonnander; G Ahlsten; B Ellertsen; T Markestad; G Jacobsen; H J Hoffman; L Bakketeig Journal: Arch Dis Child Date: 2000-07 Impact factor: 3.791
Authors: Siv Tone Natland; Lene Frost Andersen; Tom Ivar Lund Nilsen; Siri Forsmo; Geir W Jacobsen Journal: BMC Med Res Methodol Date: 2012-11-23 Impact factor: 4.615