Perhaps you should try some spelling variations:
"dos estudios americanos." » "dos estudios latinoamericanos.", "los estudios americanos."
"series estudios urbano." » "serie estudios urbano.", "seis estudios urbano.", "tres estudios urbano.", "series estudio urbano.", "series estudios peruanos.", "series estudios hispano."
"series estudios urbanos." » "serie estudios urbanos.", "seis estudios urbanos.", "tres estudios urbanos.", "series estudio urbanos.", "series estudios peruanoss.", "series estudios hispanos."

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 urbano.") or ("series estudios urbanos."))) or ("dos estudios americanos."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("series estudios urbano.") OR ("series estudios urbanos."))) OR ("dos estudios americanos."))*.
• Removing quotes may allow a broader search: (((( series estudios urbano. ) or ( series estudios urbanos. ))) or ( dos estudios americanos. ))*.