Perhaps you should try some spelling variations:
"series d'estudis urbanss." » "series d'estudis urbans.", "series estudios urbanos.", "series estudios urbanss.", "serie estudio urbanss.", "serie estudos urbanss."
"serie estudios urbano." » "serie estudios urbanos.", "serie estudio urbano.", "serie estudios peruanos."
"leyes estudios hispano." » "series estudios hispano.", "los estudios hispano.", "seis estudios hispano.", "leyes estudios hispana.", "leyes estudios hispanic."

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 urbanss.") or ("serie estudios urbano."))) or ("leyes estudios hispano."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("series d'estudis urbanss.") OR ("serie estudios urbano."))) OR ("leyes estudios hispano."))*.
• Removing quotes may allow a broader search: (((( series d'estudis urbanss. ) or ( serie estudios urbano. ))) or ( leyes estudios hispano. ))*.