Perhaps you should try some spelling variations:
"didactic e ricerca" » "didactica de ricerca", "didactica y ricerca", "didactic kg ricerca", "didactic la ricerca", "didactic di ricerca", "didactic e ricerche"
"didactic a ricerca" » "didactic atd ricerca", "didactica y ricerca", "didactic kg ricerca", "didactic la ricerca", "didactic una ricerca", "didactic tra ricerca"

Try widening your search to All Fields.

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

• If you are trying to use Boolean operators, they must be ALL CAPS: (("didactic e ricerca") OR ((("didactic _ ricerca") OR ("didactic a ricerca")))).
• Removing quotes may allow a broader search: (( didactic e ricerca ) or ((( didactic _ ricerca ) or ( didactic a ricerca )))).
• Adding a wildcard symbol may retrieve word variants: (("didactic e ricerca") or ((("didactic _ ricerca") or ("didactic a ricerca"))))*.