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

Try widening your search to All Fields.

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