S. Alaa, M. Fajrin, E. Nurhaliza, D. W. Kurniawidi, S. Rahayu, and I. W. Sudiarta, “THE STUDY OF GRAPHENE BAND GAP USING HATREE FOCK METHOD IN MOLECULAR SCALE”, IPR, vol. 3, no. 1, pp. 24–29, Feb. 2020.