Perhaps you should try some spelling variations:
"los estudios cervantinos." » "los estudios mercantiles.", "los estudios criticos.", "los estudios andinos."
"series estudios urbanos." » "serie estudios urbanos.", "seis estudios urbanos.", "leyes estudios urbanos.", "series estudio urbanos.", "series estudios peruanoss.", "series estudios hispanos."
"tres estudios urbano." » "tres estudio urbano.", "tres estudios peruanos.", "tres estudios hispano.", "otros estudios urbano.", "dos estudios urbano.", "dios estudios urbano."

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (("series estudios urbanos.") or ((("tres estudios urbano.") or ("los estudios cervantinos."))))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("series estudios urbanos.") OR ((("tres estudios urbano.") OR ("los estudios cervantinos."))))*.
• Removing quotes may allow a broader search: (( series estudios urbanos. ) or ((( tres estudios urbano. ) or ( los estudios cervantinos. ))))*.