U. Abbas Yakubu, M. Mamat, M. Afendee Mohamed, P. Liza Ghazali, and M. Rivaie, “Secant Condition Free of a Spectral Hestenses-Stiefel (SHS) Conjugate Gradient Method and its Sufficient Descent Properties”, IJET, vol. 7, no. 3.28, pp. 312–315, Aug. 2018, doi: 10.14419/ijet.v7i3.28.23467.