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