Perhaps you should try some spelling variations:
"seis estudios urbano." » "seis estudios peruanos.", "seis estudios hispano.", "seis d'estudis urbans.", "los estudios urbano.", "dos estudios urbano.", "dios estudios urbano."
"seis estudios urbanos." » "seis estudios peruanoss.", "seis estudios hispanos.", "seis d'estudis urbanss.", "los estudios urbanos.", "dos estudios urbanos.", "dios estudios urbanos."
"series estudio urbano." » "series estudios urbano.", "serie estudio urbano.", "serie estudios urbano.", "series espacio 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: (("series estudio urbano.") or ((("seis estudios urbano.") OR ("seis estudios urbanos."))))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("series estudio urbano.") OR ((("seis estudios urbano.") OR ("seis estudios urbanos.")))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"series estudio urbano.\") or (((\"seis estudios urbano.\") OR (\"seis estudios urbanos.\"))))".
• Removing quotes may allow a broader search: (( series estudio urbano. ) or ((( seis estudios urbano. ) OR ( seis estudios urbanos. )))).
• Adding a wildcard symbol may retrieve word variants: (("series estudio urbano.") or ((("seis estudios urbano.") OR ("seis estudios urbanos."))))*.