Mendoza J, Pagtakhan D, Abraham JB. 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. PJU [Internet]. 2020 Feb. 19 [cited 2025 Aug. 20];27(1):6-10. Available from: https://pjuonline.com/index.php/pju/article/view/35