Studies on the incidence of some infrabacterial pneumonias (viral-ricketsial and mycoplasmic) in Plovdiv during the period 1969-1971.
D000293:Adolescent; D000328:Adult; D002031:Bulgaria; D002648:Child; D006801:Humans; D009175:Mycoplasma Infections / Q000150:complications / Q000453:epidemiology*; D011014:Pneumonia / Q000453:epidemiology* / Q000209:etiology; D011022:Pneumonia, Rickettsial / Q000453:epidemiology; D011024:Pneumonia, Viral / Q000453:epidemiology