Adding lincense info

README.md

@@ -197,7 +197,7 @@ WIKIPEDIA SPANISH CORPUS by Carlos Daniel Hernández Mena is licensed under a Cr
 The dataset was collected by students belonging to the social service program ["Desarrollo de Tecnologías del Habla"](http://profesores.fi-b.unam.mx/carlos_mena/servicio.html). It was curated by [Carlos Daniel Hernández Mena](https://huggingface.co/carlosdanielhernandezmena) in 2020.
 
 ### Licensing Information
-[CC-BY-SA-4.0](https://creativecommons.org/licenses/by-sa/4.0/)
+[CC BY-SA 3.0](https://creativecommons.org/licenses/by-sa/3.0/deed.en)
 
 ### Citation Information
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