Update README.md

README.md

@@ -17,7 +17,7 @@ OpenScholar_Retriever is a continued pre-trained version of [facebook/contriever
 - **Developed by:** University of Washigton, Allen Institute for AI (AI2)
 - **Model type:** a masked language model. 
 - **Language(s) (NLP):** English
-- **License:** The code and model are released under Apache 2.0.
+- **License:** The code and model are released under apache-2.0. 
 - **Date cutoff:** The pre-training data is mixture of [peS2o](https://huggingface.co/datasets/allenai/peS2o), [CCNews](https://huggingface.co/datasets/vblagoje/cc_news) and [Proofpile2](https://huggingface.co/datasets/EleutherAI/proof-pile-2).
 
 ### Model Sources