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

Try widening your search to All Fields.

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