N. M. H. Yaseen and A. K. Ahmed, “Plotting the Profiles of Cartesian Surfaces by Ray-tracing”, Al-Nahrain J. Sci., vol. 17, no. 2, pp. 122–127, Jul. 2018, Accessed: May 22, 2026. [Online]. Available: https://anjs.edu.iq/index.php/anjs/article/view/451