Update README.md

README.md

@@ -79,3 +79,16 @@ rewards = [[0.5811622738838196], [0.2745276093482971], [-1.4131819009780884], [-
           3.webp: -1.41
           4.webp: -2.03
 ```
+
+## Citation
+
+```
+@misc{xu2023imagereward,
+      title={ImageReward: Learning and Evaluating Human Preferences for Text-to-Image Generation}, 
+      author={Jiazheng Xu and Xiao Liu and Yuchen Wu and Yuxuan Tong and Qinkai Li and Ming Ding and Jie Tang and Yuxiao Dong},
+      year={2023},
+      eprint={2304.05977},
+      archivePrefix={arXiv},
+      primaryClass={cs.CV}
+}
+```