Ali, S. F., K. Ijaz, F. Feroz, J. J. Fiazi, H. Ali, N. Arif, A. Z. Khan, and Raees Hafeez. “Using Spatial Covariance of Geometric and Shape Based Features for Recognition of Basic and Compound Emotions”. International Journal of Innovations in Science & Technology, vol. 6, no. 2, June 2024, pp. 754-71, https://journal.50sea.com/index.php/IJIST/article/view/831.