Saputro, H., I. Wahyudin, and A. Iskandar. “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, vol. 4, no. 1, May 2020, pp. 300-1, https://iocscience.org/ejournal/index.php/mantik/article/view/748.