Intra-rater reliability of the bath ankylosing spondylitis disease activity index (BASDAI) and the bath ankylosing spondylitis functional index (BASFI) in children with spondyloarthritis - Batthish Michelle; Rachlis Alisa; Wong Bertha; Stevens Samantha; Anderson Michelle; Feldman Brian M; Laxer Ronald M; Marcuz Joanne; Reaume Margaret; Spiegel Lynn; Whitney-Mahoney Kristi; Tse Shirley ML (BMC, 2012)