May you suggest some Spanish advanced learner's dictionaries?

I refer to a monolingual Spanish dictionary for foreigners.

I know there are a couple of good advanced learner's dictionary in English, such as the Oxford's.



If I were to learn Spanish, are there such dictionaries that can I buy?May you suggest some Spanish advanced learner's dictionaries?
If you are a very advance learner, you should check what we call "DRAE" ("Diccionario de la Real Academia Espa帽ola"). When we're not sure if a certain word exists we use check it there, because is the official dictionary of the Spanish language. It's also on the Internet.