Adekunle, A., K. Adebiyi, and M. Durowoju. “Impact of Quench Severity and Hardness on AISI 4137 Using Eco-Friendly Quenchants As Industrial Heat Treatment”. Journal of Mechanical Engineering and Sciences, vol. 4, no. 1, June 2013, pp. 409-17, doi:10.15282/jmes.4.2013.5.0038.