1. Twin pregnancy;1, MacGillivray,1986
2. Recent trends in the incidence of multiple births and their mortality;Botting, B.; Davies, I.M.; Macfarlane, A.;Arch Dis Child
3. Early detection of twin pregnancies with the use of charts of normal uterine height and waist measurement;Schneider, L.; Bessis, R.; Hajeri, H.,1978
4. Twins in sibships of Klinefelter's syndrome;Neilsen, J.;7 Med Genet,1966
5. Other associations with multiple pregnancy;Elwood, J.M.; Elwood, J.H.,1980