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

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