Columbia subject headings:
Bulgaria--Relations--Serbia.
Serbia--History--1804-1918.
Serbia--Relations--Bulgaria.
Harvard subject headings:
Bulgaria--Boundaries--Yugoslavia--Serbia.
Bulgaria--Foreign relations--1878-1944.
Eastern question (Balkan)
Russo-Turkish War, 1877-1878--Territorial questions--Bulgaria.
Russo-Turkish War, 1877-1878--Territorial questions--Yugoslavia--Serbia.
Serbia--Boundaries--Bulgaria.
Serbia--Foreign relations.
Treaty of Berlin
Treaty of San Stefano
Princeton subject headings: