Perhaps you should try some spelling variations:
"series estudios urbano." » "serie estudios urbano.", "seis estudios urbano.", "leyes estudios urbano.", "series estudios urbanos.", "series estudio urbano.", "series estudios peruanos."
"tres estudios urbano." » "tres estudios urbanos.", "tres estudio urbano.", "tres estudios peruanos.", "otros estudios urbano.", "los estudios urbano.", "dos estudios urbano."
"serie studias urbano." » "serie estudios urbanos.", "serie estudio urbano.", "serie studia urbano.", "serie estudios urbano.", "serie guias urbano."

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

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