Perhaps you should try some spelling variations:
bulgeriae » bulgariae, bulgaricae, bulgarian
vulgarische » bulgarische, bulgarischen, bulgarischer
bulgarien » bulgarian, vulgarien, bulgerien, bulgarieien
bulgaria » vulgaria, bulgeria, bulgarieia
bulgar » vulgar, bulger, bulgarie
bulgare » vulgare, bulgere, bulgariee, bulgarie, vulgares

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: ((bulgeriae OR (vulgarische OR (bulgarien OR bulgaria))) OR ((bulgar OR bulgare) OR bulge)).
• Adding a wildcard symbol may retrieve word variants: ((bulgeriae or (vulgarische or (bulgarien or bulgaria))) or ((bulgar or bulgare) or bulge))*.