Perhaps you should try some spelling variations:
bulgariae » bulgaricae, bulgarian, bulgarie
bulgerian » bulgarian, bulgarians, eulerian, bulgeian
bulgarica » bulgarisch, bulgarian, bulgarien
bulger » bulge
bulges » bulge

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 bulgaria) OR (bulgerian OR bulgarica)) OR (bulger OR bulges)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(((bulgariae OR bulgaria) or (bulgerian or bulgarica)) or (bulger or bulges))".
• Adding a wildcard symbol may retrieve word variants: (((bulgariae OR bulgaria) or (bulgerian or bulgarica)) or (bulger or bulges))*.