Biswas, M., A. Mittal, R. Sarpal, S. Agrawal, R. Pal, and K. Singh. “Whether Retrograde Pyelography Mandatory for Percutaneous Nephrolithotomy: A Randomized Clinical Trial”. International Journal of Research in Medical Sciences, vol. 4, no. 10, Dec. 2016, pp. 4477-80, doi:10.18203/2320-6012.ijrms20163314.