López-Medina, C., S. Chevret, A. Molto, J. Sieper, T. Duruöz, U. Kiltz, B. E. Zorkany, N. Hajjaj-Hassouni, R. Burgos-Vargas, J. Maldonado-Cocco, et al.,  "Identification of clinical phenotypes of peripheral involvement in patients with spondyloarthritis, including psoriatic arthritis: a cluster analysis in the worldwide ASAS-PerSpA study",  Rheumatic & Musculoskeletal Disease (RMD), vol. 7 , issue 3, pp. 1 - 12, 2021.