Riyono, Bambang, and Widia Rifkianti. “Android-Based Information System Of Online Teaching Services With Geo-Location Determination”. bit-Tech : Binary Digital - Technology 1, no. 1 (September 19, 2018): 9–18. Accessed April 20, 2024. https://jurnal.kdi.or.id/index.php/bt/article/view/6.