1. Surveillance for asthma—United States 1960–1995. CDC Surveillance Summaries, April 24, 1998;Mannino;MMWR,1998
2. The health economics of asthma and rhinitis. I. Assessing the economic impact;Weiss;J Allergy Clin Immunol,2001
3. Direct and indirect costs of asthma in Canada;Krahn;Can Med Assoc J,1996
4. Ernst P on behalf of the Canadian Asthma Consensus Group. Canadian asthma consensus report;Boulet;Can Med Assoc J,1999
5. National Asthma Education Program. Expert Panel Report II: guidelines for the diagnosis and management of asthma. Bethesda, MD: National Institutes of Health: 1997.