We found a matchYour institution may have access to this item. Find your institution then sign in to continue.TitleIncreasing twinning rates in Norway, 1967-2004: the influence of maternal age and assisted reproductive technology (ART).AuthorsTandberg A; Bjørge T; Børdahl PE; Skjaerven RPublicationActa obstetricia et gynecologica Scandinavica, 2007, Vol 86, Issue 7, p833ISSN0001-6349Publication typearticleDOI10.1080/00016340701417323