Columbia subject headings:
Bulgaria--Civilization--Congresses.
Bulgarian literature--To 1762--History and criticism--Congresses.
Church Slavic literature--Bulgaria--History and criticism--Congresses.
Harvard subject headings:
Bulgaria--Civilization--15th century--Congresses.
Bulgaria--Civilization--Congresses.
Bulgaria--History--1393-1792--Congresses.
Bulgarian literature--To 1762--History and criticism--Congresses.
Church Slavic literature--Bulgaria--History and criticism--Congresses.
Princeton subject headings: