Perhaps you should try some spelling variations:
"series estudios urbano." » "serie estudios urbano.", "seis estudios urbano.", "leyes estudios urbano.", "series estudios urbanos.", "series estudio urbano.", "series estudios peruanos."
"serie studia urbano." » "serie estudio urbano.", "serie estudios urbanos.", "serie estudios urbano."
"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.

• If you are trying to use Boolean operators, they must be ALL CAPS: (((("serie studia urbano.") OR ("series estudios urbano."))) OR ("tres estudios hispano."))~.
• Removing quotes may allow a broader search: (((( serie studia urbano. ) or ( series estudios urbano. ))) or ( tres estudios hispano. ))~.
• Adding a wildcard symbol may retrieve word variants: (((("serie studia urbano.") or ("series estudios urbano."))) or ("tres estudios hispano."))*.