Perhaps you should try some spelling variations:
union bulgarien » und bulgarien (Expand Search)
bulgarien land » bulgaren und (Expand Search), bulgarien nach (Expand Search)
land land » land und (Expand Search), und land (Expand Search)
et fur » es fur (Expand Search)
societe » society (Expand Search), societa (Expand Search)
nationen » nationalen (Expand Search), stationen (Expand Search), nation (Expand Search)

Try widening your search to All Fields.

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

• Performing a fuzzy search may retrieve terms with similar spellings: union bulgarien land land paix et fur la societe des nationen~.
• Adding a wildcard symbol may retrieve word variants: union bulgarien land land paix et fur la societe des nationen*.