Perhaps you should try some spelling variations:
national » nationale (Expand Search), nationala (Expand Search), nationaler (Expand Search)
nationalen » nationaleen (Expand Search), nationalaen (Expand Search), nationaleren (Expand Search), nationale (Expand Search)
nationalere » nationaleere (Expand Search), nationalaere (Expand Search), nationalerere (Expand Search), nationaler (Expand Search), nationale (Expand Search), nationales (Expand Search)
nationalene » nationaleene (Expand Search), nationalaene (Expand Search), nationalerene (Expand Search), nationalee (Expand Search), nationale (Expand Search), nationaler (Expand Search), nationales (Expand Search)
academic » academia (Expand Search), academie (Expand Search), akademie (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 nationalere) OR nationalene)) academic of sciences of ukraine~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(national OR ((nationalen OR nationalere) OR nationalene)) academic of sciences of ukraine".
• Adding a wildcard symbol may retrieve word variants: (national OR ((nationalen OR nationalere) OR nationalene)) academic of sciences of ukraine*.