Columbia subject headings:
Botev, Khristo, 1848-1876--Folklore.
Folk literature, Bulgarian.
Levski, Vasil, 1837-1873--Folklore.
Harvard subject headings:
Botev, Khristo, 1848-1876--Folklore.
Folk literature, Bulgarian.
Levski, Vasil Ivanov, 1837-1873--Folklore.
Princeton subject headings: