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