et. al, Zhubanova A.A. “Bioconversion of Low-Rank Coal into Humic Substances by Acinetobacter Sp. RKB”. International Journal of Advanced Science and Technology 29, no. 2 (January 13, 2020): 273 - 278. Accessed April 25, 2024. http://sersc.org/journals/index.php/IJAST/article/view/3182.