Brief Report: Repetitive Behaviour Profiles in Williams Syndrome: Cross Syndrome Comparisons with Prader-Willi and Down Syndromes - Royston, R.; Oliver, C.; Moss, J.; Adams, D.; Berg, K.; Burbidge, C.; Howlin, P.; Nelson, L.; Stinton, C.; Waite, J. (Journal of Autism and Developmental Disorders, 2018)