UKnow: A Unified Knowledge Protocol with Multimodal Knowledge Graph Datasets for Reasoning and Vision-Language Pre-Training - Gong, Biao; Tan, Shuai; Feng, Yutong; Xie, Xiaoying; Li, Yuyuan; Chen, Chaochao; Zheng, Kecheng; Shen, Yujun; Zhao, Deli (Advances in Neural Information Processing Systems, 2024)