Perhaps you should try some spelling variations:
"sociales especial urbano." » "orales especial urbano.", "sociales espacio urbano.", "sociales social urbano.", "sociales espacial urbano.", "sociales espacial urbana."
"series estudios urbanos." » "serie estudios urbanos.", "seis estudios urbanos.", "tres estudios urbanos."
"otros estudios hispano." » "los estudios hispano.", "dos estudios hispano.", "etnicos estudios hispano."

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 estudios urbanos.") or ("otros estudios hispano."))) or ("sociales especial urbano."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("series estudios urbanos.") OR ("otros estudios hispano."))) OR ("sociales especial urbano.")).
• Removing quotes may allow a broader search: (((( series estudios urbanos. ) or ( otros estudios hispano. ))) or ( sociales especial urbano. )).
• Adding a wildcard symbol may retrieve word variants: (((("series estudios urbanos.") or ("otros estudios hispano."))) or ("sociales especial urbano."))*.