1. Gastrointestinal tract complications of non-steroidal anti-inflammatory drug treatment in rheumatoid arthritis—A prospective observational cohort study;Singh;Arch Intern Med,1996
2. ARAMIS (The American Rheumatism Association Medical Information System);Fries;West J Med,1986
3. A reevaluation of aspirin therapy in rheumatoid arthritis;Fries;Arch Intern Med,1993
4. Toxic effects of azathioprine in rheumatoid arthritis: a national post-marketing perspective (Abstr.);Singh;Arthritis Rheum,1989
5. Toxicity profiles of disease modifying antirheumatic drugs in rheumatoid arthritis;Singh;J Rheumatol,1991