Add citation and methodology info

README.md

@@ -47,3 +47,31 @@ configs:
   - split: train
     path: data/train-*
 ---
+
+
+## Sampling Methodology
+
+This dataset was created using **reservoir sampling**, a statistically unbiased random sampling algorithm that guarantees each sample from the source dataset has an equal probability of being included. This ensures the 1B token sample is representative of the full dataset's characteristics.
+
+**Source Dataset**: [HuggingFaceFW/finepdfs](https://huggingface.co/datasets/HuggingFaceFW/finepdfs)
+**Sample Size**: 1B tokens
+**Content**: High-quality textbook-style pdfs
+
+Reservoir sampling enables rapid experimentation and ablation studies without processing the entire source dataset, while maintaining statistical validity of results.
+
+For details on how this dataset was used in optimal pre-training data composition research, see the [blog post](https://huggingface.co/blog/codelion/optimal-dataset-mixing/).
+
+## Citation
+
+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/).