Authors: G C Christiaens; H K Nieuwenhuis; A E von dem Borne; W H Ouwehand; F M Helmerhorst; C M van Dalen; I van der Tweel Journal: Br J Obstet Gynaecol Date: 1990-10
Authors: G A Rock; K H Shumak; N A Buskard; V S Blanchette; J G Kelton; R C Nair; R A Spasoff Journal: N Engl J Med Date: 1991-08-08 Impact factor: 91.245