Perhaps you should try some spelling variations:
"tres estudioss urbano." » "tres estudios urbanos.", "tres estudio urbano.", "tres estudios urbano.", "tres estadios urbano.", "otros estudios urbano."
"serie estudios urbano." » "serie estudios urbanos.", "serie estudio urbano.", "serie estudios peruanos."
"leyes estudios urbano." » "leyes estudios urbanos.", "leyes estudio urbano.", "leyes estudios peruanos.", "series estudios urbano.", "los estudios urbano.", "seis estudios urbano."

Try widening your search to All Fields.

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (((("tres estudioss urbano.") or ("serie estudios urbano."))) or ("leyes estudios urbano."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("tres estudioss urbano.") OR ("serie estudios urbano."))) OR ("leyes estudios urbano.")).
• Removing quotes may allow a broader search: (((( tres estudioss urbano. ) or ( serie estudios urbano. ))) or ( leyes estudios urbano. )).
• Adding a wildcard symbol may retrieve word variants: (((("tres estudioss urbano.") or ("serie estudios urbano."))) or ("leyes estudios urbano."))*.