Altintas, Yasemin, and Mehmet Bayrak. 2021. “Pre-Operative Work-up before Bariatric Surgery: Should Ultrasonography and Upper Gastrointestinal Endoscopy Be Done Routinely? ”. Annals of Medical Research 26 (3): 0408-12. http://www.annalsmedres.org/index.php/aomr/article/view/1336.