Columbia subject headings:
Art, Thracian--Bulgaria--Letnitsa.
Bulgaria--Antiquities.
Letnitsa (Bulgaria)--Antiquities.
Thracians--Religion.
Harvard subject headings:
Art, Thracian--Bulgaria--Letnitsa.
Bulgaria--Antiquities.
Letnitsa (Bulgaria)--Antiquities.
Thracians--Religion.
Princeton subject headings: