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

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

• Performing a fuzzy search may retrieve terms with similar spellings: (("series estudios urbanos.") or ((("tres estudios urbano.") OR ("los estudios urbano."))))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("series estudios urbanos.") OR ((("tres estudios urbano.") OR ("los estudios urbano."))))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"series estudios urbanos.\") or (((\"tres estudios urbano.\") OR (\"los estudios urbano.\"))))*".
• Removing quotes may allow a broader search: (( series estudios urbanos. ) or ((( tres estudios urbano. ) OR ( los estudios urbano. ))))*.