Zorina, O., and Y. Mavrykin. “Modern Approaches to Treatment and Recovery of Secondary Sludge of Domestic Sewage”. Land Reclamation and Water Management, no. 2 (December 23, 2021): 55 - 68. Accessed March 2, 2025. http://mivg.s-host.net/index.php/mivg/article/view/301.