Klippel JH, editor. Primer on the rheumatic
diseases. 12th ed. Atlanta, GA: The Arthritis Foundation; 2001.
Wegner S, Belza B, Gall E, editors. Clinical care in the rheumatic
diseases. Atlanta, GA: American College of Rheumatology; 1996.
U.S. Department of Health and Human Services. Physical activity
and health: A report of the surgeon general. Atlanta, GA: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, National Center for Chronic Disease Prevention and Health Promotion; 1996.