RT Journal Article SR Electronic T1 Problems with definitions of disease patterns in psoriatic arthritis. JF The Journal of Rheumatology JO J Rheumatol FD The Journal of Rheumatology SP 198 OP 199 VO 33 IS 1 A1 Paul Le Goff YR 2006 UL http://www.jrheum.org/content/33/1/198.1.abstract AB