title: Secular changes of twinning rates in Nordic populations.
authors: Institute of Genetics, Population Genetics Unit, Helsingfors, Finland.
authors: A W
authors: AW
authors: Eriksson
authors: C
authors: C
authors: Abbott
authors: P J
authors: PJ
authors: Kostense
authors: J O
authors: JO
authors: Fellman
mesh_terms: D000328:Adult; D001723:Birth Rate; D003710:Demography; D005260:Female; D005387:Finland; D006801:Humans; D008297:Male; D017533:Marital Status; D008423:Maternal Age; D008875:Middle Aged; D010298:Parity; D011247:Pregnancy; D012537:Scandinavian and Nordic Countries; D014427:Twins