Perhaps you should try some spelling variations:
bulgariae » bulgaricae, bulgarian, bulgarie, bulgareiae, bulgeriae, bulgarieiae
bulgerian » bulgarian, bulgarians, eulerian
bulgarische » bulgarischen, ungarische, bulgareische, bulgerische, bulgarieische
bulgaria » bulgareia, bulgeria, bulgarieia
bulgar » bulgare, bulger, bulgarie

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

• If you are trying to use Boolean operators, they must be ALL CAPS: (((bulgariae OR bulgerian) OR (bulgarische OR bulgaria)) OR ((bulgar OR vulgar) OR bulge)).
• Adding a wildcard symbol may retrieve word variants: (((bulgariae or bulgerian) or (bulgarische or bulgaria)) or ((bulgar or vulgar) or bulge))*.