Prasetyo, Heru, and Elisa Usada. “Perancangan Sistem Pintu Gerbang Dengan Sensor Radio Frequency Identification (RFID) Menggunakan Metode Waterfall”. JURNAL INFOTEL 5, no. 2 (November 10, 2013): 24-32. Accessed July 3, 2020. https://ejournal.st3telkom.ac.id/index.php/infotel/article/view/5.