1. 1. Ancans, G., Bobrovs, V., & Ivanovs, G. (2013). Spectrum usage in mobile broadband communication systems. Latvian Journal of Physics and Technical Sciences, 50(3), 49–58.
2. 2. Report ITU-R M.2290-0. (2013). Future Spectrum Requirements Estimate for Terrestrial IMT. International Telecommunications Union. Available at http://www.itu.int/dms_pub/itu-r/opb/rep/R-REP-M.2290-2014-PDF-E.pdf.
3. 3. Recommendation ITU-R M.2083-0. (2015). IMT Vision – Framework and Overall Objectives of the Future Development of IMT for 2020 and Beyond. International Telecommunications Union. Available at https://www.itu.int/dms_pubrec/itu-r/rec/m/R-RECM.2083-0-201509-I!!PDF-E.pdf.
4. 4. Report ITU-R M.2376-0. (2015). Technical Feasibility of IMT in Bands above 6 GHz. International Telecommunications Union. Available at https://www.itu.int/dms_pub/itur/opb/rep/R-REP-M.2376-2015-PDF-E.pdf
5. 5. Resolution COM6/20 (WRC-15). (2015). Studies on Frequency-related Matters for International Mobile Telecommunications Identification Including Possible Additional Allocations to the Mobile Services on a Primary Basis in Portion(s) of the Frequency Range between 24.25 and 86 GHz for the Future Development of International Mobile Telecommunications for 2020 and beyond. International Telecommunications Union. Switzerland, Geneva.