Hamdani, Ahmad Helman, and Agus Didit Haryanto. “The Spontaneous Combustion Potency of Lignite Coal Based on FTIR”. European Journal of Environment and Earth Sciences 3, no. 5 (October 5, 2022): 37–40. Accessed June 14, 2025. https://ej-geo.org/index.php/ejgeo/article/view/326.