Perhaps you should try some spelling variations:
"dos estudios hispana." » "dos estudios hispano.", "dos estudios hispanicos.", "dos estudios historia.", "los estudios hispana."
"seis estudios urbano." » "seis estudios urbanos.", "seis estudio urbano.", "seis estudios peruanos.", "los estudios urbano.", "dios estudios urbano.", "pons estudios urbano."
"serie estudios urbano." » "serie estudios urbanos.", "serie estudio urbano.", "serie estudios peruanos."

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: (((("seis estudios urbano.") or ("serie estudios urbano."))) or ("dos estudios hispana."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("seis estudios urbano.") OR ("serie estudios urbano."))) OR ("dos estudios hispana.")).
• Removing quotes may allow a broader search: (((( seis estudios urbano. ) or ( serie estudios urbano. ))) or ( dos estudios hispana. )).
• Adding a wildcard symbol may retrieve word variants: (((("seis estudios urbano.") or ("serie estudios urbano."))) or ("dos estudios hispana."))*.