Frieyadie F. PENERAPAN MODEL WATEFALL PADA RANCANG BANGUN SISTEM INFORMASI PENJUALAN ONLINE HID BULLAES. jitk [Internet]. 2016Aug.15 [cited 2025Jan.31];2(1):1-4. Available from: https://ejournal.nusamandiri.ac.id/index.php/jitk/article/view/226