Perhaps you should try some spelling variations:
"los estudios peruanoss." » "los estudios americanoss.", "los estudios ensayoss.", "los estudios cervantinoss."
"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 estudios urbano."

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