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