Perhaps you should try some spelling variations:
"serie estudio urbano." » "serie estudios urbano.", "serie espacio urbano.", "series estudios urbano.", "serie studia urbano.", "serie estado urbano."
"serie studias urbano." » "serie estudios urbano.", "serie studia urbano.", "series estudios urbano.", "serie guias urbano."
"serie estudios urbanos." » "series estudioss urbanos.", "serie studias urbanos.", "serie estados urbanos."

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

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