Perhaps you should try some spelling variations:
"series estudios peruanoss." » "series estudios peruanos.", "seis estudios peruanoss.", "leyes estudios peruanoss.", "sociales estudios peruanoss."
"serie estudios urbanos." » "serie estudio urbanos.", "serie estudios peruanoss.", "serie estudios hispanos."
"tres estudios urbano." » "tres estudio urbano.", "tres estudios peruanos.", "tres estudios hispano.", "otros estudios urbano.", "los estudios urbano.", "dos estudios urbano."

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 estudios peruanoss.") OR ("serie estudios urbanos."))) OR ("tres estudios urbano."))~.
• Removing quotes may allow a broader search: (((( series estudios peruanoss. ) or ( serie estudios urbanos. ))) or ( tres estudios urbano. ))~.
• Adding a wildcard symbol may retrieve word variants: (((("series estudios peruanoss.") or ("serie estudios urbanos."))) or ("tres estudios urbano."))*.