The Talmud on the safe period in the menstrual cycle.
D000818:Animals; D030762:Estrous Cycle; D004971:Estrus; D005260:Female; D006801:Humans; D007246:Infertility; D007247:Infertility, Female; D008597:Menstrual Cycle; D012067:Religion
ESTRUS CYCLE; RELIGION; STERILITY, FEMALE