[Use of proportional sampling in clinico-statistical research].
D004899:Erythroblastosis, Fetal / Q000453:epidemiology*; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D008433:Mathematics; D008722:Methods; D011247:Pregnancy; D012494:Sampling Studies; D014586:USSR
Primenenie proportsional'nogo tipologicheskogo otbora v kliniko-statisticheskikh issledovaniiakh.