Perhaps you should try some spelling variations:
"didactics e ricerca" » "didactics _ ricerca", "didactics 2 ricerca", "didactics 4 ricerca", "didactics la ricerca", "didactics di ricerca", "didactics e ricerche"
"didactics 3 ricerca" » "didactics _ ricerca", "didactics 2 ricerca", "didactics 4 ricerca", "didactics la ricerca", "didactics di ricerca", "didactics 22 ricerca"

Try widening your search to All Fields.

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

• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"didactics e ricerca\") OR (\"didactics 3 ricerca\"))".
• Removing quotes may allow a broader search: (( didactics e ricerca ) OR ( didactics 3 ricerca )).
• Adding a wildcard symbol may retrieve word variants: (("didactics e ricerca") OR ("didactics 3 ricerca"))*.