Feng, Y., Z. Cai, H. Li, Z. Du, and X. Liu. “Response Surface Optimization of Fluidized Roasting Reduction of Low-Grade Pyrolusite Coupling With Pretreatment of Stone Coal”. Journal of Mining and Metallurgy, Section B: Metallurgy, Vol. 49, no. 1, June 2013, p. 33, https://aseestant.ceon.rs/index.php/jmm/article/view/2042.