Guo, Yaping, et al. “Evaluation of Flue Gas Desulfurization Gypsum As a Low-Cost Precipitant for Phosphorus Removal from Anaerobic Digestion Effluent Filtrate”. International Journal of Agricultural and Biological Engineering, vol. 17, no. 4, Sept. 2024, pp. 198-06, https://ijabe.migration.pkpps03.publicknowledgeproject.org/index.php/ijabe/article/view/8227.