Perhaps you should try some spelling variations:
bulgariae » bulgaricae, bulgaria, bulgarian, bulgareiae, vulgariae, bulgeriae
vulgaria » bulgaria, vulgaris, vulgari
bulgarisch » bulgarische, bulgarischen, bulgareisch, vulgarisch, bulgerisch
bulgar » bulgare, vulgar, bulger

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 (vulgaria OR bulgarisch)) OR (bulgar OR bulge)).
• Adding a wildcard symbol may retrieve word variants: ((bulgariae or (vulgaria or bulgarisch)) or (bulgar or bulge))*.