Susilawati, Susilawati, et al. “Synthesis of M-Hexaferrites Material Based on Natural Iron Sand With Metal Co Doping Using the Coprecipitation Method”. Jurnal Penelitian Pendidikan IPA, vol. 7, no. 1, Nov. 2020, pp. 1-4, doi:10.29303/jppipa.v7i1.461.