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

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 ((("dios estudios peruanos.") OR ("dios estudios americanos."))))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("series estudios urbano.") OR ((("dios estudios peruanos.") OR ("dios estudios americanos."))))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"series estudios urbano.\") or (((\"dios estudios peruanos.\") OR (\"dios estudios americanos.\"))))*".
• Removing quotes may allow a broader search: (( series estudios urbano. ) or ((( dios estudios peruanos. ) OR ( dios estudios americanos. ))))*.