1. Weight, sitting height, head size, foot length, and menstrual age of the human embryo;Streeter;Contributions to Embryology,1920
2. Probabilities of fetal mortality;French;Public Health Reports,1962
3. Provoked Abortions Amongst 1,447 Married Women;Awan,1969
4. Pregnancy losses in New York City, 1960;Erhardt;American Journal of Public Health,1963
5. Cumulative rate computed from data for H.I.P. study,1968