Irwan Gunawan, Fadilla Maharani Putri, and Armansyah. “Outgoing Letter Approval System at Class I Climatology Stations in North Sumatra Using the Prototype Method”. Journal of Information Systems and Technology Research 3, no. 1 (January 31, 2024): 10–19. Accessed August 3, 2025. https://journal.aira.or.id/index.php/jistr/article/view/719.