Weng, R., H. Wei, S. Huang, H. Yu, L. Bing, W. Luo, and J. Chen. “GRET: Global Representation Enhanced Transformer”. Proceedings of the AAAI Conference on Artificial Intelligence, vol. 34, no. 05, Apr. 2020, pp. 9258-65, doi:10.1609/aaai.v34i05.6464.