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