Ali, H., V. Sritharan, M. Hariharan, M. Elshaikh, and W. Khairunizam. 2018. “Facial Expression Recognition Based on Radon and Discrete Wavelet Transform Using Support Vector Machines”. Journal of Telecommunication, Electronic and Computer Engineering (JTEC) 10 (1-13):49-54. https://jtec.utem.edu.my/jtec/article/view/4121.