Perhaps you should try some spelling variations:
"los estudios americanos." » "los estudios latinoamericanos."
"serie d'estudis urbans." » "serie estudio urbano.", "serie estudios urbano.", "serie estudios urbans.", "serie estudio urbans.", "serie estudos urbans."
"series estudios urbanos." » "serie estudios urbanos.", "seis estudios urbanos.", "tres estudios urbanos."

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 d'estudis urbans.") OR ((("series estudios urbanos.") OR ("los estudios americanos."))))~.
• Removing quotes may allow a broader search: (( serie d'estudis urbans. ) or ((( series estudios urbanos. ) or ( los estudios americanos. ))))~.
• Adding a wildcard symbol may retrieve word variants: (("serie d'estudis urbans.") or ((("series estudios urbanos.") or ("los estudios americanos."))))*.