Kusumo, F. N., A. Triayudi, and R. Sahara. “Application On Payment UPS Online For Students Android-Based National University Information System: Application On Payment UPS Online For Students Android-Based National University Information System”. Jurnal Mantik, vol. 4, no. 1, May 2020, pp. 926-35, https://www.ejournal.iocscience.org/index.php/mantik/article/view/829.