Akhmad, T. A., D. Apriano, and E. Abdurachman. “ANALISIS DAN PERANCANGAN SISTEM E-PROCUREMENT PADA PT. XYZ”. Journal of Business Strategy and Execution, vol. 3, no. 2, June 2011, pp. 176 -01, https://journal.binus.ac.id/index.php/JBSE/article/view/209.