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

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 peruanos.") OR ("tres estudios urbanos."))))~.
• Removing quotes may allow a broader search: (( serie studias urbano. ) or ((( series estudios peruanos. ) or ( tres estudios urbanos. ))))~.
• Adding a wildcard symbol may retrieve word variants: (("serie studias urbano.") or ((("series estudios peruanos.") or ("tres estudios urbanos."))))*.