Perhaps you should try some spelling variations:
"series d'estudis urbans." » "serie estudios urbans.", "serie estudio urbans.", "serie estudos urbans.", "series estudios urbanos.", "series estudio urbano."
"series estudios urbano." » "serie estudios urbano.", "seis estudios urbano.", "leyes estudios urbano.", "series estudios urbanos.", "series estudio urbano.", "series estudios peruanos."
"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 ("series estudios urbano."))) or ("tres estudios hispano."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("series d'estudis urbans.") OR ("series estudios urbano."))) OR ("tres estudios hispano.")).
• Removing quotes may allow a broader search: (((( series d'estudis urbans. ) or ( series estudios urbano. ))) or ( tres estudios hispano. )).
• Adding a wildcard symbol may retrieve word variants: (((("series d'estudis urbans.") or ("series estudios urbano."))) or ("tres estudios hispano."))*.