Update readme with preprint bibtex

README.md

@@ -1101,8 +1101,17 @@ for row in ds:
 
 ## Citation
 
+If you use WorldSpeech in your research, please cite:
+
 ```bibtex
-Coming soon.
+@misc{asonitis2026worldspeech,
+      title={WorldSpeech: A Multilingual Speech Corpus from Around the World}, 
+      author={Antonis Asonitis and Luca A. Lanzendörfer and Frédéric Berdoz and Roger Wattenhofer},
+      year={2026},
+      eprint={2605.09167},
+      archivePrefix={arXiv},
+      url={https://arxiv.org/abs/2605.09167}
+}
 ```