AL- Nuaimi, M.A. , Al-kubaisi, B.F. and Al-heety, S.O. (2021) “Manufacture of Spongy Gravel from Obsidian to Produce Lightweight and Thermal-Insulating Concrete”, Iraqi Journal of Science, (7), pp. 2286–2295. doi:10.24996/ijs.2021.62.7.17.