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