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

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

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