multimodal_nlp paper link https://www.aclweb.org/anthology/P19-1656.pdf https://arxiv.org/pdf/1811.09362.pdf https://arxiv.org/pdf/1806.00064.pdf https://arxiv.org/pdf/1806.06176.pdf https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=9053762 https://www.aclweb.org/anthology/P19-1046.pdf https://arxiv.org/pdf/1808.03920.pdf