Fourth, Fifth and Eighth: Bunker, Emma C.; Kawami, Trudy S.; with Linduff, Katheryn M.; Ancient Bronzes of the Eastern Eurasian Steppes from the Arthur M. Sackler Collections. The Arthur M. Sackler Foundation, New York, 1997; cat. no. F15b, illustrated; cat. no. 246, illustrated; cat. no. F17b, illustrated.
Sixth: Carter, Dagny; The Symbol of the Beast. The Ronald Press Co.; New York, 1957, pl. 21:c.