Columbia subject headings:
Harvard subject headings:
Bulgaria--Territorial expansion--History.
Bulgarians--Macedonia.
Macedonia--Politics and government.
Serbia--Territorial expansion--History.
Vŭtreshna makedono-odrinska revoli︠u︡t︠s︡ionna organizat︠s︡ii︠a︡.
Princeton subject headings:
Macedonia--History--1878-1912.
Macedonia--History--1912-1945.
Macedonia--Relations--Yugoslavia--Serbia.
Macedonian question.
Serbia--Relations--Macedonia.
Vŭtreshna makedono-odrinska revoli︠u︡t︠s︡ionna organizat︠s︡ii︠a︡.