Keum, Ki-mun, Chang-bok Jang, Ki-Bong Kim Kim, and Ohseok Kwon. “BLE Beacon-Based Etiquette System of Smart Devices”. International Journal of Engineering and Technology 7, no. 3.24 (August 10, 2018): 249–254. Accessed August 17, 2025. https://mail.sciencepubco.com/index.php/IJET/article/view/22657.