title: Smoking among Norwegian schoolchildren 1975-1980. I. Extent of smoking in the age group 12-15 years, 1975.
mesh_terms: D000293:Adolescent; D000367:Age Factors; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D009664:Norway; D012737:Sex Factors; D012907:Smoking