Columbia subject headings:
Bulgaria--Foreign relations--1878-1944.
Diplomats--Bulgaria--Biography.
Shopov, Atanas, 1855-1922--Correspondence.
Shopov, Atanas, 1855-1922--Diaries.
Harvard subject headings:
Balkan Peninsula--History--War of 1912-1913--Sources.
Bulgaria--Foreign relations--1878-1944.
Bulgaria--History--Ferdinand I, 1887-1918--Sources.
Macedonia--History--1878-1912--Sources.
Macedonian question.
Shopov, Atanas, 1855-1922--Correspondence.
Princeton subject headings: