Abutu, J., S. Lawal, M. Ndaliman, R. A. Lafia-Araga, and M. A. Oluleye. “Tribological Properties of Friction Materials Developed from Non- Asbestos Materials Using Response Surface Methodology”. International Journal of Engineering Materials and Manufacture, Vol. 5, no. 2, June 2020, pp. 40-49, doi:10.26776/ijemm.05.02.2020.02.