Perhaps you should try some spelling variations:
"series estudios urbano." » "seis estudios urbano.", "leyes estudios urbano.", "sociales estudios urbano.", "series estudios urbanos.", "series estudio urbano.", "series estudios peruanos."
"serie estudios urbano." » "serie estudios urbanos.", "serie estudio urbano.", "serie estudios peruanos."
"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: (((("series estudios urbano.") or ("serie estudios urbano."))) or ("tres estudios hispano."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("series estudios urbano.") OR ("serie estudios urbano."))) OR ("tres estudios hispano.")).
• Removing quotes may allow a broader search: (((( series estudios urbano. ) or ( serie estudios urbano. ))) or ( tres estudios hispano. )).
• Adding a wildcard symbol may retrieve word variants: (((("series estudios urbano.") or ("serie estudios urbano."))) or ("tres estudios hispano."))*.