Mohammed Nadzri, Nur Izzati, Khairul Azami Sidek, and Ahmad Fadzil Ismail. 2018. “Biometric Recognition for Twins Inconsideration of Age Variability Using PPG Signals”. Journal of Telecommunication, Electronic and Computer Engineering (JTEC) 10 (1-5):97-100. https://jtec.utem.edu.my/jtec/article/view/3638.