Perhaps you should try some spelling variations:
"series estudios urbanos." » "serie estudios urbanos.", "tres estudios urbanos.", "leyes estudios urbanos."
"serie studias urbano." » "serie estudios urbano.", "serie estudio urbano.", "serie studia urbano.", "serie guias urbano."
"seis estudios urbanos." » "los estudios urbanos.", "dos estudios urbanos.", "dios estudios 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: (((("series estudios urbanos.") OR ("seis estudios urbanos."))) OR ("serie studias urbano."))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"series estudios urbanos.\") OR (\"seis estudios urbanos.\"))) or (\"serie studias urbano.\"))~".
• Removing quotes may allow a broader search: (((( series estudios urbanos. ) OR ( seis estudios urbanos. ))) or ( serie studias urbano. ))~.
• Adding a wildcard symbol may retrieve word variants: (((("series estudios urbanos.") OR ("seis estudios urbanos."))) or ("serie studias urbano."))*.