Perhaps you should try some spelling variations:
"series estudios peruanos." » "series estudios urbanos.", "series estudios americanos.", "series estudios ensayos.", "serie estudios peruanos.", "seis estudios peruanos.", "tres estudios peruanos."
"series estudios urbano." » "serie estudios urbano.", "seis estudios urbano.", "tres estudios urbano.", "series estudios urbanos.", "series estudio urbano.", "series estudios hispano."
"serie studias urbano." » "serie estudios urbanos.", "serie estudio urbano.", "serie studia urbano.", "serie estudios urbano.", "serie guias urbano."

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 studias urbano.") OR ((("series estudios urbano.") OR ("series estudios peruanos."))))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"serie studias urbano.\") or (((\"series estudios urbano.\") OR (\"series estudios peruanos.\"))))~".
• Removing quotes may allow a broader search: (( serie studias urbano. ) or ((( series estudios urbano. ) OR ( series estudios peruanos. ))))~.
• Adding a wildcard symbol may retrieve word variants: (("serie studias urbano.") or ((("series estudios urbano.") OR ("series estudios peruanos."))))*.