Perhaps you should try some spelling variations:
"series estudio urbano." » "series estudios urbano.", "serie estudio urbano.", "serie estudios urbano.", "series estudios urbanos.", "series espacio urbano."
"serie desafio cubano." » "serie desafio susana.", "serie desafio ciudadano."
"tres estudios hispano." » "otros estudios hispano.", "los estudios hispano.", "dos estudios hispano.", "tres estudios hispana.", "tres 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 estudio urbano.") or ("serie desafio cubano."))) or ("tres estudios hispano."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("series estudio urbano.") OR ("serie desafio cubano."))) OR ("tres estudios hispano.")).
• Removing quotes may allow a broader search: (((( series estudio urbano. ) or ( serie desafio cubano. ))) or ( tres estudios hispano. )).
• Adding a wildcard symbol may retrieve word variants: (((("series estudio urbano.") or ("serie desafio cubano."))) or ("tres estudios hispano."))*.