Avivanto, Ahmad, Agung Triayudi, and Ira Diana Sholihati. 2020. “Operation and Maintenance Operational Management Application for Building Facilities Based on Android: Operation and Maintenance Operational Management Application for Building Facilities Based on Android”. Jurnal Mantik 4 (1):798-808. https://www.ejournal.iocscience.org/index.php/mantik/article/view/854.