Vikainis, Roberts, Sergejs Talapins, and Romans Matvejevs. “PRESENCE DETECTION SYSTEMS - EFFICIENCY OF USE, BEST PRACTICE”. BORDER SECURITY AND MANAGEMENT 4, no. 9 (February 17, 2023): 135–143. Accessed January 2, 2025. https://journals.ru.lv/index.php/BSM/article/view/7039.