This cong with its anthropomorphic masks is very similar in the style of carving and size to one illustrated by James C. Y. Watt in Chinese Jades from the Collection of the Seattle Art Museum, Seattle, 1989, p. 29, no. 2. Another in the Freer Gallery of Art is illustrated by Julia K. Murray in "Neolithic Chinese Jades in the Freer Gallery of Art", Orientations, November 1983, pp. 4-12, fig. 116. J. Rawson in Chinese Jade from the Neolithic to the Qing, British Museum, 1995, p. 124, illustrates line drawings of two similar cong from Zhejiang Yuhang Yaoshan. See, also, the similar example illustrated by Yang Boda in Chinese Archaic Jades from the Kwan Collection, Art Gallery, The Chinese University of Hong Kong, 1994, no. 50.