RT Journal Article SR Electronic T1 Late onset spondyloarthropathy: comparison with early onset patients JF Annals of the Rheumatic Diseases JO Ann Rheum Dis FD BMJ Publishing Group Ltd and European League Against Rheumatism SP 572 OP 572 DO 10.1136/ard.56.9.572 VO 56 IS 9 A1 L J KAY A1 D J WALKER YR 1997 UL http://ard.bmj.com/content/56/9/572.abstract AB