Columbia subject headings:
Bulgaria--Boundaries--Romania.
Bulgaria--History--Boris III, 1918-1943.
Dobruja (Romania and Bulgaria)--History--20th century.
Romania--Boundaries--Bulgaria.
Romania--History--1914-1944.
World War, 1914-1918--Territorial questions--Dobruja (Romania and Bulgaria)
Harvard subject headings:
Bulgaria--Boundaries--Romania.
Bulgaria--Foreign relations--Romania.
Bulgaria--History--Boris III, 1918-1943.
Dobruja (Romania and Bulgaria)--History--20th century.
Romania--Boundaries--Bulgaria.
Romania--Foreign relations--Bulgaria.
Romania--History--1914-1944.
World War, 1914-1918--Territorial questions--Dobruja (Romania and Bulgaria)
Princeton subject headings:
Bulgaria--Foreign relations--Romania.
Dobruja (Romania and Bulgaria)--History--20th century.
Romania--Foreign relations--Bulgaria.