Ismail, Ismail, Suhono H. Supangkat, Hendrawan Hendrawan, and Basuki Y. Iskandar. 2013. “Refining Spectrum Fee to Increase Utilization Efficiency by Adopting ITU-R SM 2012-2 Case Study: Cellular Service in Indonesia”. Journal of ICT Research and Applications 4 (1):1-22. https://doi.org/10.5614/itbj.ict.2010.4.1.1.