S.- wei Xue, M.- bo Zhang, Y.- kun Luo, N. Li, and S.- yi Shi, “A comparative study of ultrasound-guided percutaneous nephrolithotripsy and x-ray-guided percutaneous nephrolithotripsy in the treatment of complex renal calculi without hydronephrosis”, Pak J Med Sci, vol. 38, no. 8, Oct. 2022.