Perhaps you should try some spelling variations:
"tres estudios hispanic." » "tres estudios hispanicos.", "tres estudios hispano.", "tres studies hispanic.", "otros estudios hispanic.", "los estudios hispanic.", "dos estudios hispanic."
"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."

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