RT Journal Article SR Electronic T1 How many angels could dance on the head of a pin? JF The Journal of Rheumatology JO J Rheumatol FD The Journal of Rheumatology SP 2240 OP 2240 VO 29 IS 10 A1 George E Ehrlich YR 2002 UL http://www.jrheum.org/content/29/10/2240.abstract AB