“RANCANGANSISTEM INFORMASI E-PROCUREMENT BERORIENTASI OBJECT ( STUDI KASUS : PT. KRAKATAU TIRTA INDUSTRI )”. Jurnal Ilmiah Sains Dan Teknologi, vol. 2, no. 2, Sept. 2018, pp. 76-98, https://ejournal.lppm-unbaja.ac.id/index.php/saintek/article/view/97.