Smoking by primary schoolchildren prevalence and associated respiratory symptoms.
D000397:Air Pollution; D002648:Child; D003371:Cough / Q000453:epidemiology; D004739:England; D005260:Female; D006801:Humans; D008297:Male; D012140:Respiratory Tract Diseases / Q000453:epidemiology*; D012737:Sex Factors; D012907:Smoking / Q000453:epidemiology*; D012923:Social Class