1. Prevalence of disability and associated health conditions;MMWR Morb Mortal Wkly Rep,1994
2. Rheumatoid arthritis in adults in the United States 1960–1962;Engel,1966
3. The prevalence of knee osteoarthritis in the elderly. The Framingham Osteoarthritis Study;Felson;Arthritis Rheum,1987
4. Knee osteoarthritis and physical functioning;Davis;J Rheumatol,1991
5. Comorbidity in arthritis;Gabriel;J Rheumatol,1999