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