Nurrohmah, Isnaeni, et al. “Measuring the E-Government Maturity in Indonesia Using the Ranking of E-Government of Indonesia (PeGI)”. American Scientific Research Journal for Engineering, Technology, and Sciences, vol. 32, no. 1, May 2017, pp. 49-63, https://www.asrjetsjournal.org/American_Scientific_Journal/article/view/2978.