1. Shbeeb M, Uramoto KM, Gibson LE, O'Fallon WM, Gabriel SE (2000)The epidemiology of psoriatic arthritis in Olmsted County, Minnesota, USA, 1982–1991. J Rheumatol 27(5): 1247–1250
2. Leonard DG, O'Duffy JD, Rogers RS (1978) Prospective analysis of psoriatic arthritis in patients hospitalized for psoriasis. Mayo Clin Proc 53(8): 511–518
3. Gladman D (2004) Psoriatic Arthritis. In Isenberg DA, et al (eds). Oxford Textbook of Rheumatology, 3rd edition. UK Oxford University Press, Oxford
4. Veale D, Yanni G, Rogers S, Barnes L, Bresnihan B, Fitzgerald O (1993) Reduced synovial membrane macrophage numbers, ELAM-1 expression, and lining layer hyperplasia in psoriatic arthritis as compared with rheumatoid arthritis. Arthritis Rheum 36(7): 893–900
5. Buskila D, Langevitz P, Gladman DD, Urowitz S, Smythe HA (1992) Patients with rheumatoid arthritis are more tender than those with psoriatic arthritis. J Rheumatol 19(7): 1115–1119