Perhaps you should try some spelling variations:
"series estudioss peruanoss." » "series estudios peruanos.", "serie estudios peruanoss.", "seis estudios peruanoss.", "serie estudio peruanoss.", "serie estudioss peruanoss.", "seis estudioss peruanoss.", "tres estudioss peruanoss."
"series estudios urbanos." » "serie estudios urbanos.", "seis estudios urbanos.", "tres estudios urbanos."
"dos estudios urbanos." » "los estudios urbanos."

You may be able to get more results by adjusting your search query.

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