Perhaps you should try some spelling variations:
national » nationala (Expand Search), nationaler (Expand Search), nation (Expand Search)
nationalen » nationalaen (Expand Search), nationaleren (Expand Search), nationen (Expand Search)
nationalesen » nationalaesen (Expand Search), nationaleresen (Expand Search), nationesen (Expand Search), nationaler (Expand Search), nationalist (Expand Search), rationalen (Expand Search), nationaleren (Expand Search), nationalisten (Expand Search), nationalaen (Expand Search)
nationales » nationalaes (Expand Search), nationaleres (Expand Search), nationes (Expand Search), nationaler (Expand Search), nationalist (Expand Search), nationala (Expand Search)
nationale » nationalae (Expand Search), nationalere (Expand Search), natione (Expand Search)

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

• Performing a fuzzy search may retrieve terms with similar spellings: (national OR (nationalen OR (nationalesen OR (nationales OR nationale)))) connaissance front~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(national OR (nationalen OR (nationalesen OR (nationales OR nationale)))) connaissance front".
• Adding a wildcard symbol may retrieve word variants: (national OR (nationalen OR (nationalesen OR (nationales OR nationale)))) connaissance front*.