R. Izamshah, N. Husna, M. Hadzley, M. Amran, M. Shahir, and M. Amri. “Effects of Cutter Geometrical Features on Machining Polyetheretherketones (PEEK) Engineering Plastic”. Journal of Mechanical Engineering and Sciences, vol. 6, no. 1, June 2014, pp. 863-72, doi:10.15282/jmes.6.2014.12.0082.