M. Dawahdeh, M. Mamat, A. Alhawarat, M. Rivaie, and M. Afendee Mohamed, “An Extension of Polak-Ribière-Polyak Method”, IJET, vol. 7, no. 3.28, pp. 348–353, Aug. 2018, doi: 10.14419/ijet.v7i3.28.27383.