TY  - JOUR
A1  - Tandberg, A.
A1  - Bjørge, T.
A1  - Børdahl, P.E.
A1  - Skjaerven, R.
T1  - Increasing twinning rates in Norway, 1967-2004: The influence of maternal age and assisted reproductive technology (ART)
Y1  - 2007
DO  - 10.1080/00016340701417323
JF  - Acta Obstetricia Et Gynecologica Scandinavica
VL  - 86
IS  - 7
SP  - 833
EP  - -839

ER  -