Perhaps you should try some spelling variations:
"seis estudios cervantinos." » "seis estudios mercantiles.", "seis estudios criticos.", "seis estudios andinos.", "los estudios cervantinos.", "dos estudios cervantinos.", "dios estudios cervantinos."
"series estudios urbanos." » "serie estudios urbanos.", "tres estudios urbanos.", "leyes estudios urbanos."
"serie estudos urbano." » "serie estudios urbano.", "serie estudio urbano.", "serie d'estudis urbans.", "serie estado urbano."

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

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