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