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