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