Li, Qiang, Fuli Yang, Guoxiang Zheng, and Zhengjun Guan. 2019. “Effects of Urea Ammonia Pretreatment on the Batch Anaerobic Fermentation Efficiency of Corn Stovers”. International Journal of Agricultural and Biological Engineering 12 (4):169-73. https://ijabe.migration.pkpps03.publicknowledgeproject.org/index.php/ijabe/article/view/4835.