Update README.md

README.md

@@ -208,4 +208,6 @@ then load, featurize, split, fit, and evaluate the a catboost model
 ## Citation
 Chem. Res. Toxicol. 2022, 35, 9, 1614–1624
 Publication Date:September 2, 2022
-https://doi.org/10.1021/acs.chemrestox.2c00207
+https://doi.org/10.1021/acs.chemrestox.2c00207
+
+dataset license: not specified