Prevalence of respiratory symptoms in Norway.
D000328:Adult; D000367:Age Factors; D000368:Aged; D001991:Bronchitis / Q000453:epidemiology; D003371:Cough / Q000453:epidemiology; D004641:Emigration and Immigration; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009093:Mucus / Q000378:metabolism; D009664:Norway; D009790:Occupations; D012140:Respiratory Tract Diseases / Q000453:epidemiology* / Q000401:mortality; D012424:Rural Population; D012494:Sampling Studies; D012737:Sex Factors; D012907:Smoking / Q000150:complications / Q000453:epidemiology; D012923:Social Class; D011795:Surveys and Questionnaires; D014481:United States; D014505:Urban Population