Perhaps you should try some spelling variations:
"series estudios urbano." » "serie estudios urbano.", "seis estudios urbano.", "leyes estudios urbano.", "series estudio urbano.", "series estudios peruanos.", "series estudios hispano."
"tres estudios urbanos." » "tres estudio urbanos.", "tres estudios peruanoss.", "tres estudios hispanos.", "otros estudios urbanos.", "los estudios urbanos.", "dos estudios urbanos."
"serie studias urbano." » "serie estudio urbano.", "serie studia urbano.", "serie estudios urbano.", "serie guias urbano."

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

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