Bálint, Csaba, and Mátyás Kiglics. “A Geometric Method for Accelerated Sphere Tracing of Implicit Surfaces”. Acta Cybernetica 25, no. 2 (August 4, 2021): 171-185. Accessed June 27, 2022. https://cyber.bibl.u-szeged.hu/index.php/actcybern/article/view/4203.