Ren, Jianguo, et al. “Optimization of Weathered Coal Biodegradation by Penicillium Aculeatum 13-2-1 and UV-Visible Spectral Characteristics of Active Degraded Products”. BioResources, vol. 18, no. 1, Jan. 2023, pp. 1260-78, https://ojs.bioresources.com/index.php/BRJ/article/view/22155.