Syed Kamran Habib, Umar Sherwani, Zainab Jamal and Saif Ur Rehman 2023. Evaluation of Clonidine as an Alternative to Fentanyl as Adjuvant in Sub Arachnoid Block in Adults Scheduled for Elective Procedures: A Randomized Controlled Trial: Clonidine and Fentanyl compared as adjuvants in spinal anesthesia. Advances in Clinical Medical Research. 4, 2 (Jun. 2023), 16–19.