Perhaps you should try some spelling variations:
"series estudios peruanos." » "series estudios urbanos.", "series estudios americanos.", "series estudios ensayos.", "serie estudios peruanos.", "seis estudios peruanos.", "tres estudios peruanos."
"series estudios urbano." » "serie estudios urbano.", "seis estudios urbano.", "tres estudios urbano.", "series estudios urbanos.", "series estudio urbano.", "series d'estudis urbans."
"reales estudios hispano." » "reales estudio hispano.", "rurales estudios hispano.", "locales estudios hispano.", "reales estudios hispana.", "reales estudios hispanic."

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 urbano.") OR ("series estudios peruanos."))) or ("reales estudios hispano."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("series estudios urbano.") OR ("series estudios peruanos."))) OR ("reales estudios hispano.")).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"series estudios urbano.\") OR (\"series estudios peruanos.\"))) or (\"reales estudios hispano.\"))".
• Removing quotes may allow a broader search: (((( series estudios urbano. ) OR ( series estudios peruanos. ))) or ( reales estudios hispano. )).
• Adding a wildcard symbol may retrieve word variants: (((("series estudios urbano.") OR ("series estudios peruanos."))) or ("reales estudios hispano."))*.