“Manufacture of Spongy Gravel from Obsidian to Produce Lightweight and Thermal-Insulating Concrete”.
Iraqi Journal of Science, no. 7 (July 31, 2021): 2286–2295. Accessed August 14, 2025.
https://www.ijs.uobaghdad.edu.iq/index.php/eijs/article/view/3602.