1. The fetus of multiple gestations;Guttmacher;Obst. & Gynec.,1958
2. Perinatal loss in modern obstetrics;Nesbitt,1957
3. Foetal wastage in twin pregnancy;Tow;J. Obst. & Gynaec. Brit. Emp.,1959
4. Twin placenta in perinatal mortality;Benirschke;New York J. Med.,1961
5. Accurate recording of twin placenta;Benirschke;Obst, & Gynec.,1961