“A comparative and retrospective study on the efficacy of caudal epidural steroid injection plus ganglion impar block versus ganglion impar block in patients with coccydynia”, Ann Med Res , vol. 29, no. 12, pp. 1413–1417, Dec. 2022, Accessed: Oct. 21, 2025. [Online]. Available: http://www.annalsmedres.org/index.php/aomr/article/view/4177