Wardhana, I Gede Adhitya Wisnu, et al. “Submodul Prima Lemah Dan Submodul Hampir Prima Pada Z‐modul M_2x2 (Z_9)”. EIGEN MATHEMATICS JOURNAL, vol. 1, no. 1, June 2018, pp. 28-30, doi:10.29303/emj.v1i1.6.