Hwang, Yao-Hsin, and Chung-Hua Chiang. “Tracking Methods to Study the Surface Regression of the Solid-Propellant Grain”. International Journal of Engineering and Technology Innovation 4, no. 4 (October 1, 2014): 213–222. Accessed April 17, 2024. https://ojs.imeti.org/index.php/IJETI/article/view/144.