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

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

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