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