Ismail, Rifky, et al. “An Investigation on the Premature Failure of Spur Gear in Coal Stacker Reclaimer: Mechanical Properties and Microstructure Analysis”. American Scientific Research Journal for Engineering, Technology, and Sciences, vol. 59, no. 1, Sept. 2019, pp. 252-61, https://www.asrjetsjournal.org/American_Scientific_Journal/article/view/5036.