Perhaps you should try some spelling variations:
"series estudioss urbano." » "serie estudios urbano.", "seis estudios urbano.", "serie estudio urbano.", "series estudios urbanos.", "series estudio urbano.", "serie estudioss urbano.", "seis estudioss urbano.", "tres estudioss urbano."
"series estudios etnicos." » "series estudios criticos.", "series estudios biblicos.", "serie estudios etnicos.", "seis estudios etnicos.", "tres estudios etnicos."
"series estudios urbano." » "serie estudios urbano.", "seis estudios urbano.", "tres estudios urbano.", "series estudios urbanos.", "series estudio urbano.", "series estudios peruanos."

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (("series estudioss urbano.") or ((("series estudios urbano.") or ("series estudios etnicos."))))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("series estudioss urbano.") OR ((("series estudios urbano.") OR ("series estudios etnicos."))))*.
• Removing quotes may allow a broader search: (( series estudioss urbano. ) or ((( series estudios urbano. ) or ( series estudios etnicos. ))))*.