switched to github link to prevent wrong pick up

README.md

@@ -56,7 +56,7 @@ If you use this dataset, please cite the following paper:
 
 [1]: https://arxiv.org/abs/1909.04054
 [2]: https://aclanthology.org/D19-1383
-[3]: https://arxiv.org/abs/1710.06071
+[3]: https://github.com/Franck-Dernoncourt/pubmed-rct
 [4]: https://aclanthology.org/N18-3011/
 [5]: https://www.figure-eight.com/
 [6]: https://github.com/allenai/sequential_sentence_classification