Todorov, Plamen, and Anastas Batalov. “A Comparative Study Between Ultrasound Guided and Landmarks Guided Intraarticular Sacroiliac Injections in Spondyloarthritis Patients”. Archives of Clinical and Experimental Orthopaedics 4, no. 1 (March 17, 2020): 001–008. Accessed December 8, 2025. https://www.exporthopaedicjournal.com/index.php/aceo/article/view/aceo-aid1007.