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

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

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