Ryu, H., S. Kang, H. Kang, and C. D. Yoo. “Semantic Grouping Network for Video Captioning”. Proceedings of the AAAI Conference on Artificial Intelligence, vol. 35, no. 3, May 2021, pp. 2514-22, https://ojs.aaai.org/index.php/AAAI/article/view/16353.