WASET
    Khadijat T. Bamigbade and  Olufade F. W. Onifade,  Improved Feature Extraction Technique for Handling Occlusion in Automatic Facial Expression Recognition.   journal   = {International Journal of Computer and Information Engineering}, [online]. World Academy of Science, Engineering and Technology.
    March 2019, vol. 148(4). 218 - 221
    [viewed 16 April 2024]. Available from: https://publications.waset.org/pdf/10010270.