Perhaps you should try some spelling variations:
"dos estudios hispanic." » "dos estudios hispanicos.", "dos estudios hispano.", "dos studies hispanic.", "los estudios hispanic."
"serie d'estudis urbans." » "serie estudios urbanos.", "serie estudio urbano.", "serie estudio urbans.", "serie estudos urbans."
"serie estudios urbano." » "serie estudios urbanos.", "serie estudio urbano.", "serie estudios peruanos."

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (((("serie d'estudis urbans.") or ("serie estudios urbano."))) or ("dos estudios hispanic."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("serie d'estudis urbans.") OR ("serie estudios urbano."))) OR ("dos estudios hispanic."))*.
• Removing quotes may allow a broader search: (((( serie d'estudis urbans. ) or ( serie estudios urbano. ))) or ( dos estudios hispanic. ))*.