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

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

• Performing a fuzzy search may retrieve terms with similar spellings: (("series estudioss urbano.") or ((("tres estudios urbanos.") or ("dos estudios peruanos."))))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("series estudioss urbano.") OR ((("tres estudios urbanos.") OR ("dos estudios peruanos."))))*.
• Removing quotes may allow a broader search: (( series estudioss urbano. ) or ((( tres estudios urbanos. ) or ( dos estudios peruanos. ))))*.