Added citation to paper

README.md

@@ -149,3 +149,18 @@ Each sample provides:
 - one metadata entry in `metadata.csv`
 
 The metadata describes the global topology of each sample through its total genus, number of connected components, and component-wise genus distribution.
+
+## Citation
+
+If you use DONUT, please cite the paper [FILTR: Extracting Topological Features from Pretrained 3D Models](https://arxiv.org/abs/2604.22334):
+
+```bibtex
+@misc{martinez2026filtr,
+  title={FILTR: Extracting Topological Features from Pretrained 3D Models},
+  author={Martinez, Louis and Ovsjanikov, Maks},
+  year={2026},
+  eprint={2604.22334},
+  archivePrefix={arXiv},
+  url={https://arxiv.org/abs/2604.22334}
+}
+```