A TUTORIAL ON MATHEMATICAL MODELING OF 5G/6G MILLIMETER WAVE AND TERAHERTZ CELLULAR SYSTEMS Article Moltchanov D., Sopin E., Begishev V., Samuylov A., Koucheryavy Y., Samouylov K. IEEE Communications Surveys and Tutorials. Institute of Electrical and Electronics Engineers Inc.. Vol. 24. 2022. P. 1072-1116