Perhaps you should try some spelling variations:
"series estudio urbano." » "series estudios urbano.", "serie estudio urbano.", "serie estudios urbano."
"series espacio urbano." » "series spain urbano.", "versus espacio urbano.", "sociales espacio urbano.", "series espacio urbanismo."
"dios estudios urbanos." » "dos estudios urbanos.", "los estudios urbanos.", "otros 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: (((("series estudio urbano.") OR ("series espacio urbano."))) or ("dios estudios urbanos."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("series estudio urbano.") OR ("series espacio urbano."))) OR ("dios estudios urbanos."))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"series estudio urbano.\") OR (\"series espacio urbano.\"))) or (\"dios estudios urbanos.\"))*".
• Removing quotes may allow a broader search: (((( series estudio urbano. ) OR ( series espacio urbano. ))) or ( dios estudios urbanos. ))*.