1. Twin pregnancy: Complications and treatment;Powers;Obstet. Gynecol,1973
2. Perinatal factors and neonatal morbidity in twin pregnancy;Ho;Am. J. Obstet. Gynecol,1975
3. Role of bed rest in twin gestation;Jeffrey;Obstet. Gynecol,1974
4. Outcome of twin birth;Petterson;Acta Paediatr. Scand,1976
5. Outcome of twin birth;Petterson,1977