1. Birth weight, gestation time and survival in sibs;Karn;Ann. Eugen., Lond,1951
2. Birth weight and gestation time in relation to maternal age, parity and infant survival;Karn;Ann. Eugen., Lond,1951
3. Risk of stillbirth in twin pregnancy related to sex and maternal age;Lowe;Brit. J. Soc. Med,1951