Dellisya, Tasya, and Yohannes Yahya Welim. “RANCANG BANGUN SISTEM INFORMASI PENJUALAN PADA HEYHO GROUP INDONESIA”. IDEALIS : InDonEsiA JournaL Information System, vol. 1, no. 4, Sept. 2018, pp. 404-10, https://jom.fti.budiluhur.ac.id/IDEALIS/article/view/1191.