Nguyen, Trung Dung, et al. “Study on Theory of Separation Efficiency of Twin-Spiral Separator in a Grinding – Separation Apatite Process”. JST: Engineering And Technology For Sustainable Development, vol. 32, no. 1, Mar. 2022, pp. 38-42, doi:10.51316/jst.156.etsd.2022.32.1.6.