title: [Changes in the length of pregnancy in the Czech Socialist Republic from 1967 to 1980].
mesh_terms: D003604:Czechoslovakia; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D011247:Pregnancy; D011273:Pregnancy, Prolonged
vernacular_title: Zmĕny podílů v délce tĕhotenství v CSR v letech 1967-1980.