The frequency and the character of malformations in multiple births.
D000013:Congenital Abnormalities / Q000145:classification / Q000453:epidemiology / Q000235:genetics*; D003604:Czechoslovakia; D004200:Diseases in Twins; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D011247:Pregnancy; D012737:Sex Factors; D014310:Triplets