กิตติวรปรีดา วิโรจน์. “Personal Alarm Device for Elderly People Who Live Alone”. Vocational Education Central Region Journal 4, no. 2 (December 29, 2020): 66–78. Accessed April 26, 2024. https://so06.tci-thaijo.org/index.php/IVECJournal/article/view/246243.