Fix citation to reference blog post

README.md

@@ -116,7 +116,18 @@ This sampled dataset is ideal for:
 
 ## Citation
 
-If you use this dataset, please cite both the original FineWiki dataset and mention the sampling methodology.
+If you use this model/dataset, please cite:
+
+```bibtex
+@article{sharma2025billion,
+  title={The 1 Billion Token Challenge: Finding the Perfect Pre-training Mix},
+  author={Sharma, Asankhaya},
+  year={2025},
+  url={https://huggingface.co/blog/codelion/optimal-dataset-mixing/}
+}
+```
+
+For more details, see the [blog post](https://huggingface.co/blog/codelion/optimal-dataset-mixing/).
 
 ## License