Khan, Ahmad Ali, Mudassar Sajjad, Muhammad Yasrab, and Muhammad Sarwar Alvi. 2019. “RETROGRADE AIR INJECTION FOR IDENTIFYING PRECISELY POSTERIOR CALYX: A VERY USEFUL TOOL WHILE PERFORMING MINI-PERCUTANEOUS NEPHROLITHOTOMY”. Pakistan Armed Forces Medical Journal 69 (3): 600-04. https://pafmj.org/PAFMJ/article/view/3038.