Mendoza, Jonathan, Danison Pagtakhan, and Jose Benito Abraham. “Comparative Analysis of the Efficacy and Safety Profile of Upper Calyceal Versus Lower Calyceal Access in the Percutaneous Nephrolithotomy (PCNL): A Retrospective Cross-Sectional Study”. Philippine Journal of Urology 27, no. 1 (February 19, 2020): 6-10. Accessed April 25, 2024. https://pjuonline.com/index.php/pju/article/view/35.