Kamran, M., A. Fawwad, S. I. Haider, T. Hussain, and J. Ahmed. “Upper Gastrointestinal Endoscopy; A Study from a rural population of Sindh, Pakistan”. Pakistan Journal of Medical Sciences, Vol. 37, no. 1, Dec. 2020, doi:10.12669/pjms.37.1.3297.