Perhaps you should try some spelling variations:
"los estudios americanos." » "los estudios latinoamericanos."
"los estudios peruanos." » "los estudios urbanos.", "los estudios ensayos.", "los estudios cervantinos."
"series estudio urbano." » "series estudios urbano.", "serie estudio urbano.", "serie estudios urbano.", "series estudios urbanos.", "series espacio urbano."

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