Respiratory symptoms in a group of American secondary school students: the overwhelming association with cigarette smoking.
D000293:Adolescent; D001741:Black or African American; D000367:Age Factors; D003371:Cough / Q000453:epidemiology / Q000209:etiology; D004522:Educational Status; D005006:Ethnicity; D005260:Female; D006801:Humans; D008297:Male; D009518:New York; D010290:Parents; D011014:Pneumonia / Q000150:complications; D012140:Respiratory Tract Diseases / Q000453:epidemiology / Q000209:etiology*; D012574:Schools; D012737:Sex Factors; D012907:Smoking / Q000150:complications* / Q000453:epidemiology; D012923:Social Class; D013334:Students; D044465:White People