1. Zhang, J., Yin, Z., Chen, P., Nichele, S.: Emotion recognition using multi-modal data and machine learning techniques: a tutorial and review. Inf. Fusion 59, 103–126 (2020)
2. Franzoni, V., Biondi, G., Milani, A.: Emotional sounds of crowds: spectrogram-based analysis using deep learning. Multimedia Tools Appl. 79(47), 36063–36075 (2020)
3. Veltmeijer, E.A., Gerritsen, C., Hindriks, K.: Automatic emotion recognition for groups: a review. IEEE Trans. Affect. Comput. (2021)
4. Carroll, M.: How Tumblr and Pinterest are fueling the image intelligence problem. Forbes. https://www.forbes.com/sites/matthewcarroll/2012/01/17/tumblr-pinterest-are-fueling-the-image-intelligence-problem-the-crippling-image-intelligence-problem/?sh=fbc4a9d640ca (2012). Accessed 9 January 2023
5. Friesen, E., Ekman, P.: Facial action coding system: a technique for the measurement of facial movement. Palo Alto 3(2), 5 (1978)