Sociological investigations on the physical development of school children.
D000293:Adolescent; D000375:Aging; D000886:Anthropometry; D001827:Body Height; D002031:Bulgaria; D002648:Child; D005006:Ethnicity; D005260:Female; D006128:Growth; D006801:Humans; D008297:Male; D012621:Seasons; D012737:Sex Factors; D014586:USSR