Perhaps you should try some spelling variations:
"series estudios americanos." » "series estudios latinoamericanos.", "serie estudios americanos.", "seis estudios americanos.", "leyes estudios americanos."
"series estudioss urbano." » "serie estudios urbano.", "seis estudios urbano.", "serie estudio urbano.", "series estudios urbanos.", "series estudio urbano.", "serie estudioss urbano.", "seis estudioss urbano.", "leyes estudioss urbano."
"tres estudios urbano." » "tres estudios urbanos.", "tres estudio urbano.", "tres estudios peruanos.", "otros estudios urbano.", "los estudios urbano.", "dos estudios 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 estudioss urbano.") or ((("series estudios americanos.") or ("tres estudios urbano."))))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("series estudioss urbano.") OR ((("series estudios americanos.") OR ("tres estudios urbano."))))*.
• Removing quotes may allow a broader search: (( series estudioss urbano. ) or ((( series estudios americanos. ) or ( tres estudios urbano. ))))*.