Perhaps you should try some spelling variations:
national » nationale (Expand Search), nationala (Expand Search), nationalen (Expand Search)
nationalesa » nationaleesa (Expand Search), nationalaesa (Expand Search), nationalenesa (Expand Search), nationale (Expand Search), nationalen (Expand Search), nationala (Expand Search), nationalea (Expand Search), nationalena (Expand Search), nationalista (Expand Search)
nationales » nationalees (Expand Search), nationalaes (Expand Search), nationalenes (Expand Search), nationale (Expand Search), nationalen (Expand Search), nationalist (Expand Search)
nationaler » nationaleer (Expand Search), nationalaer (Expand Search), nationalener (Expand Search), nationale (Expand Search), nationalen (Expand Search), nationala (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 ((nationalesa OR nationales) OR nationaler)) academic of sciences of ukraine~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(national OR ((nationalesa OR nationales) OR nationaler)) academic of sciences of ukraine".
• Adding a wildcard symbol may retrieve word variants: (national OR ((nationalesa OR nationales) OR nationaler)) academic of sciences of ukraine*.