Perhaps you should try some spelling variations:
"serie estudios urbano." » "serie estudios urbanos.", "serie estudio urbano.", "serie estudios peruanos."
"series estudios urbano." » "series estudios urbanos.", "series estudio urbano.", "series estudios peruanos.", "seis estudios urbano.", "tres estudios urbano.", "leyes estudios urbano."
"reales estudios urbano." » "reales estudios urbanos.", "reales estudio urbano.", "reales estudios peruanos.", "rurales estudios urbano.", "locales estudios urbano."

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