Nicholaus, M. R., E. Nfuka, and K. A. Aliila. “Modelling of Indoor Positioning Systems Based on Location Fingerprinting”. International Journal of Computer (IJC), Vol. 39, no. 1, Sept. 2020, pp. 59-78, https://ijcjournal.org/index.php/InternationalJournalOfComputer/article/view/1819.