Arlievsky, M., G. Vlasova, P. Vlasov, and R. Kurtenkov. “Researching and Developing the Process of Production Superphosphate Using Spent Sulphuric Acid”. Chemical Bulletin of Kazakh National University, Vol. 63, no. 3, Mar. 2018, pp. 31-36, doi:https://doi.org/10.15328/cb833.