А. А. Овсянников and П. А. Новиков, “Implementation of the indoor navigation algorithm based on bluetooth low energy 4.0. technology”, Computer Tools in Education, no. 4, pp. 37–51, Aug. 2015, Accessed: Sep. 11, 2026. Available: http://cte.eltech.ru/ojs/index.php/kio/article/view/1462