Li, Jiaming, Guangxue Li, Feng Jiang, Jia Bu, Mingzhu Zhao, Hualu Zhan, and Yang Chu. 2012. “Preparation of Carbon Molecular Sieve for Pressure Swing Adsorption Concentrating Low-Concentration Methane”. Asian Journal of Chemistry 24 (12):5493-96. https://asianpubs.org/index.php/ajchem/article/view/9913.