Perhaps you should try some spelling variations:
"series d'estudis urbans." » "series estudios urbans.", "serie estudios urbans.", "serie estudio urbans.", "series estudio urbano.", "series estudios urbano."
"seis estudios urbanos." » "los estudios urbanos.", "dos estudios urbanos.", "dios estudios urbanos."
"tres estudios hispano." » "otros estudios hispano.", "los estudios hispano.", "dos estudios hispano.", "tres estudios hispana.", "tres estudios hispanic."

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