Perhaps you should try some spelling variations:
"valor adaptativo y grado superior." » "valor optativo y grado superior.", "valor educativo y grado superior.", "valor citativo y grado superior.", "valor adaptativa y grado superior.", "valor adaptativo al grado superior.", "valor adaptativas y grado superior.", "valor adaptativo el grado superior.", "valor adaptativo y granos superior."
"valores normativos de grado superior." » "valores formativos de grado superior.", "valores normativo de grado superior.", "valores informativos de grado superior."

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: (("valores normativos de grado superior.") or ("valor adaptativo y grado superior."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("valores normativos de grado superior.") OR ("valor adaptativo y grado superior.")).
• Removing quotes may allow a broader search: (( valores normativos de grado superior. ) or ( valor adaptativo y grado superior. )).
• Adding a wildcard symbol may retrieve word variants: (("valores normativos de grado superior.") or ("valor adaptativo y grado superior."))*.