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