Luo, B., J. Zhu, T. Yang, S. Zhao, C. Hu, X. Zhao, and Y. Gao. “Learning Deep Hierarchical Features With Spatial Regularization for One-Class Facial Expression Recognition”. Proceedings of the AAAI Conference on Artificial Intelligence, vol. 37, no. 5, June 2023, pp. 6065-73, doi:10.1609/aaai.v37i5.25749.