Wei, D., H. Liang, S. Li, F. Li, F. Ding, S. Wang, Z. Liu, and P. Zhang. “Microstructure and Tribological Behavior of W-Mo Alloy Coating on Powder Metallurgy Gears Based on Double Glow Plasma Surface Alloying Technology”. Journal of Mining and Metallurgy, Section B: Metallurgy, Vol. 55, no. 2, May 2019, p. 227, https://aseestant.ceon.rs/index.php/jmm/article/view/19353.