Columbia subject headings:
Harvard subject headings:
Bulgaria--Emigration and immigration.
Bulgarian Americans.
Bulgarians--United States
Bulgarians--United States--History--20th century.
Immigrants--United States--History--20th century
United States--Emigration and immigration.
Princeton subject headings:
Bulgaria--Emigration and immigration.
Bulgarians--United States--History--20th century.
Immigrants--United States--History--20th century.
United States--Emigration and immigration.