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."
"series estudioss urbano." » "serie estudios urbano.", "seis estudios urbano.", "serie estudio urbano.", "series estudios urbano.", "series estudio urbano.", "serie estudioss urbano.", "seis estudioss urbano.", "leyes estudioss 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.

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