Update README.md

README.md

@@ -42,7 +42,7 @@ This version of T-FREX has been fine-tuned for [token classification](https://hu
 
 ## Model variations
 
-T-FREX includes a set of released, fine-tuned models which are compared in the original study (to be published).
+T-FREX includes a set of released, fine-tuned models which are compared in the original study (pre-print available at http://arxiv.org/abs/2401.03833).
 
 - [**t-frex-bert-base-uncased**](https://huggingface.co/quim-motger/t-frex-bert-base-uncased)
 - [**t-frex-bert-large-uncased**](https://huggingface.co/quim-motger/t-frex-bert-large-uncased)