Perhaps you should try some spelling variations:
"ley estudio urbanos." » "ley estudios urbanos.", "ley estudio urbano.", "ley estudios peruanos.", "y estudio urbanos.", "leyes estudios urbanos.", "hoy estudios urbanos."
"serie estudios urbano." » "serie estudios urbanos.", "serie estudio urbano.", "serie estudios peruanos."
"series estudios hispano." » "seis estudios hispano.", "tres estudios hispano.", "leyes estudios hispano.", "series estudios hispana.", "series estudios hispanic."

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

• Performing a fuzzy search may retrieve terms with similar spellings: (((("ley estudio urbanos.") or ("serie estudios urbano."))) or ("series estudios hispano."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("ley estudio urbanos.") OR ("serie estudios urbano."))) OR ("series estudios hispano."))*.
• Removing quotes may allow a broader search: (((( ley estudio urbanos. ) or ( serie estudios urbano. ))) or ( series estudios hispano. ))*.