Natural family planning in the 1990s.
Ryder
B
B
Department of Endocrinology, City Hospital NHS Trust, Birmingham, UK.
Campbell
H
H
D000349:Africa; D001208:Asia; D002582:Cervix Mucus / Q000502:physiology; D005060:Europe; D005193:Family Planning Services / Q000639:trends*; D005260:Female; D005298:Fertility; D006801:Humans; D008297:Male; D012252:Natural Family Planning Methods; D011247:Pregnancy / Q000706:statistics & numerical data*