Alvarez, Dellys Adriana, and Juan Camilo Suárez Escudero. “Undifferentiated Spondyl Arthropathy, Ankylosing Spondylitis and Psoriatic Arthropathy. Clinical, Diagnostic and Radiological Description”. Medicina UPB 25, no. 2 (December 15, 2006): 171–183. Accessed May 26, 2026. https://revistas.upb.edu.co/index.php/medicina/article/view/2348.