A bi of similar size (23.4 cm.), and date, ascribed to north-west China, which appears to be of similar stone, is illustrated by J. Rawson, Chinese Jade from the Neolithic to the Qing, British Museum, 1995, p. 156, no. 7:7. See, also, another similar bi (22 cm.) ascribed to the Liangzhu Culture, in the Qing Court collection, illustrated in The Complete Treasures of the Palace Museum - 40 - Jadeware (I), Hong Kong, 1995, p. 29, no. 26.