Cervini, C., G. Leardini, A. Mathieu, L. Punzi, and R. Scarpa. “Psoriatic Arthritis: Epidemiological and Clinical Aspects in a Cohort of 1.306 Italian Patients”. Reumatismo 57, no. 4 (1): 283-290. Accessed August 5, 2021. https://www.reumatismo.org/index.php/reuma/article/view/reumatismo.2005.283.