PHAN, T. T.; THANG, D. V. Joint Spatial Geometric and Max-margin Classifier Constraints for Facial Expression Recognition Using Nonnegative Matrix Factorization. International Journal of Machine Learning and Networked Collaborative Engineering, [S. l.], v. 3, n. 03, p. 125–134, 2019. Disponível em: https://mlnce.net/index.php/Home/article/view/104. Acesso em: 15 jan. 2025.