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.", "leyes estudios peruanos."
"series estudios urbanos." » "serie estudios urbanos.", "seis estudios urbanos.", "leyes estudios urbanos."
"tres estudios hispano." » "otros estudios hispano.", "los estudios hispano.", "dos estudios hispano.", "tres estudios hispana.", "tres estudios hispanic."

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