Syafrudin, A., H. R. Kurnia, and D. Sunaryo. “Implementing Scrum in Government Institution: The Case of the Directorate General of Tax”. International Journal Technology and Business, vol. 1, no. 2, Oct. 2017, pp. 40-49, http://ijtb.esqbs.ac.id/index.php/IJTB/article/view/184.