Perhaps you should try some spelling variations:
"series estudios hispana." » "series estudios hispano.", "series estudios hispanicos.", "series estudios historia.", "seis estudios hispana.", "tres estudios hispana.", "sociales estudios hispana."
"leyes estudios urbanos." » "leyes estudio urbanos.", "leyes estudios peruanoss.", "leyes estudios hispanos.", "los estudios urbanos.", "seis estudios urbanos.", "tres estudios urbanos."
"serie estudios urbano." » "serie estudio urbano.", "serie estudios peruanos.", "serie estudios hispano."

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

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