Perhaps you should try some spelling variations:
"seis estudios urbano." » "seis estudio urbano.", "seis estudios peruanos.", "seis estudios hispano.", "los estudios urbano.", "dos estudios urbano.", "dios estudios urbano."
"series estudios urbano." » "series estudio urbano.", "series estudios peruanos.", "series estudios hispano.", "tres estudios urbano.", "leyes estudios urbano.", "sociales 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: (((("seis estudios urbano.") or ("series estudios urbano."))) or ("serie estudios urbanos."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("seis estudios urbano.") OR ("series estudios urbano."))) OR ("serie estudios urbanos."))*.
• Removing quotes may allow a broader search: (((( seis estudios urbano. ) or ( series estudios urbano. ))) or ( serie estudios urbanos. ))*.