Alab’evV. R., AshihminV. D., PlaksienkoO. V., and TishinR. A. “Prospects for Industrial Methane Production in the Mine n.A. V.M.Bazhanov Using Vertical Surface Wells”. Journal of Mining Institute 241 (February 25, 2020): 3. Accessed January 19, 2021. http://pmi.spmi.ru/index.php/pmi/article/view/4948.