Columbia subject headings:
Bulgaria--History--Ferdinand I, 1887-1918.
Danev, Stoi︠a︡n Petrov, 1858-1949.
Statesmen--Bulgaria--Biography.
Harvard subject headings:
Bulgaria--Foreign relations--1878-1944.
Bulgaria--Politics and government--1878-1944.
Danev, Stoi︠a︡n Petrov, 1858-1949.
Statesmen--Bulgaria--Biography.
Princeton subject headings: