XUE, S.- WEI; ZHANG, M.- BO; LUO, Y.- KUN; LI, N.; SHI, S.- YI. A comparative study of ultrasound-guided percutaneous nephrolithotripsy and x-ray-guided percutaneous nephrolithotripsy in the treatment of complex renal calculi without hydronephrosis. Pakistan Journal of Medical Sciences, v. 38, n. 8, 15 Oct. 2022.