Saputro, Heru, Iwan Wahyudin, and Agus Iskandar. 2020. “Development of a Web-Based Online Library Information System at the National University Using the Waterfall Method: Development of a Web-Based Online Library Information System at the National University Using the Waterfall Method”. Jurnal Mantik 4 (1):300-310. https://www.ejournal.iocscience.org/index.php/mantik/article/view/748.