Govedarica, O., V. Rajaković-Ognjanović, B. Lekić, and B. Babić. “Water Softening by Nanofiltration – Case Study”. Water Research and Management, vol. 9, no. 3-4, Dec. 2019, pp. 43-50, http://wrmjournal.com/index.php/wrm/article/view/268.