Bhattacharya, Jayanta. “Non-Fuel Mineral Production under Pandemic in the US: Perception Belies Reality”. Journal of Mines, Metals and Fuels 70, no. 4 (June 20, 2022): 157–160. Accessed May 3, 2024. http://www.informaticsjournals.com/index.php/jmmf/article/view/30061.