Luthvina, Ridha, et al. “Model Penilaian Pemasok Bahan Olah Karet (Bokar)”. Jurnal Optimasi Sistem Industri, vol. 18, no. 2, Oct. 2019, pp. 186–198, http://josi.ft.unand.ac.id/index.php/josi/article/view/177.