Dong, S.-W., Hu, S.-W. , Liu, S.-P., Wu, C.-C., Lin, C.-T., Chen, K.-C. and Ho, C.-H. 2022. A Safe and Effective Two-Step Tract Dilation Technique in Totally Ultrasound-Guided Percutaneous Nephrolithotomy. Urology Journal. 19, 06 (Dec. 2022), 420–426. DOI:https://doi.org/10.22037/uj.v19i06.7205.