Black pottery stem cups of this shape have been found in burials of the late phase of the Dawenkou culture in Shandong province; Shandongsheng wenwu guanlichu and Jinanshi bowuguan, Dawenkou, Beijing, Wenwu Press, 1974, pl. 75:8. See, also, Terukazu Akiyama et al., Arts of China--Neolithic Cultures to the Tang Dynasty, Tokyo, Kodansha International Ltd., 1968, pl. 35; Kaogu xuebao, 1986, no. 3k, p. 330, fig. 21; and Kwang-chih Chang, The Archaeology of Ancient China, 4th edition, New Haven, Yale University Press, 1986, p. 171