“The Effects of Sedation With Propofol and Propofol- Ketamin Combination on Postoperative Cognitive Function in Elderly Patients Undergoing Spinal Anesthesia”. Annals of Medical Research 28, no. 6 (June 28, 2021): 1201–1205. Accessed May 9, 2025. http://www.annalsmedres.org/index.php/aomr/article/view/3819.