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.", "tres estudios peruanos."
"series estudios urbanos." » "serie estudios urbanos.", "seis estudios urbanos.", "tres estudios urbanos.", "series estudio urbanos.", "series estudios hispanos.", "series d'estudis urbanss."
"series estudios urbano." » "serie estudios urbano.", "seis estudios urbano.", "tres estudios urbano.", "series estudio urbano.", "series estudios hispano.", "series d'estudis urbans."

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