Perhaps you should try some spelling variations:
"series estudios urbano." » "seis estudios urbano.", "leyes estudios urbano.", "sociales estudios urbano.", "series estudio urbano.", "series estudios peruanos.", "series d'estudis urbans."
"serie estudios urbanos." » "serie estudio urbanos.", "serie estudios peruanoss.", "serie d'estudis urbanss."
"tres estudios hispano." » "otros estudios hispano.", "los estudios hispano.", "dos estudios hispano.", "tres estudios hispana.", "tres estudios hispanic."

Try widening your search to All Fields.

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

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