Phan, Khanh, Luu Tung, and Huynh An. “PPG Signal and Application in the Medical Field”. VNUHCM Journal of Engineering and Technology 6, no. 1 (June 30, 2023): 1826-1843. Accessed April 7, 2026. https://et.vnuhcmjournal.com.vn/index.php/et/article/view/1084.