Pradeepa, M.G., Maneesh M. Sinha, and Krishnaprasad Tyagi. “The Halo Sign During a Percutaneous Nephrolithotomy Puncture”. Canadian Urological Association Journal 10, no. 3-4 (March 14, 2016): E130. Accessed April 24, 2024. https://cuaj.ca/index.php/journal/article/view/3353.