Columbia subject headings:
Harvard subject headings:
Bulgaria--History--1762-1878.
Levski, Vasil Ivanov, 1837-1873.
Revolutionaries--Bulgaria--Biography
Princeton subject headings:
Karaivanov, Vasil Genchev, 1847-1933.
Levski, Vasil, 1837-1873.
Revolutionaries--Bulgaria--Biography.