Card: add arXiv citation

README.md

@@ -51,3 +51,19 @@ the reward from `solution`.
 ## License
 
 MIT, inherited from GroundCUA (see `LICENSE`).
+
+## Citation
+
+This RL corpus is introduced in [GroundGUI: GUI Grounding by High-Quality Data and Distillation-to-Reinforcement Learning](https://arxiv.org/abs/2610.19100). If you use it, please cite:
+
+```bibtex
+@misc{xie2026groundguiguigroundinghighquality,
+      title={GroundGUI: GUI Grounding by High-Quality Data and Distillation-to-Reinforcement Learning},
+      author={Qingsong Xie and Jiahao Tian and Jiacheng Tang and Zhifeng Li and Madalina Ciobanu and Navan Preet Singh and Qingqing Mao and Ritankar Das},
+      year={2026},
+      eprint={2610.19100},
+      archivePrefix={arXiv},
+      primaryClass={cs.AI},
+      url={https://arxiv.org/abs/2610.19100},
+}
+```