Epidemiologic study of ischemic heart disease among the plain and highland rural population of south Bulgaria.
D000328:Adult; D000368:Aged; D000531:Altitude; D002031:Bulgaria; D003327:Coronary Disease / Q000453:epidemiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012424:Rural Population