Bhatti, A. Y., A. B. Waqar, S. A. Zia, N. Hussain, and T. Zulfiqar. “A Cross Sectional Study on the Risk Factors of Gallbladder Stone”. International Journal of Research in Medical Sciences, vol. 4, no. 11, Dec. 2016, pp. 5041-6, doi:10.18203/2320-6012.ijrms20163814.