First and second: W. Samolin and I.M. Drew, "Eurasian Animal Style Plaques I", Monumenta Serica XXIV, 1965, pl. 6:C and pp. 12-3; and pl. 8:B and pp. 182-3, respectively.
Third: D. Carter, The Symbol of the Beast, New York, 1957, p. 98, pl. 22e.
All: E.C. Bunker et al., Ancient Bronzes of the Eastern Eurasian Steppes from the Arthur M. Sackler Collections, The Arthur M. Sackler Foundation, 1997, pp. 261-2, no. 224; p. 272, no. 239; and p. 280, no. 248, respectively.
First and second: Arthur M. Sackler Gallery, 31 December 1996 - 31 December 1999.