For a Song dynasty prototype of this form, see Yang Xin, Li Yihua and Xu Naixiang, The Art of the Dragon, Boston, 1988, p. 82, no. 60, where a qingbai globular ewer with a dragon head as a spout, and its body as the handle, is illustrated. A Yuan ewer covered with a white glaze with a slight bluish tinge and surmounted by a dragon forming both the handle and the spout, is in the Musée Guimet, Michel Calmann Collection, no. 416, and is illustrated in Oriental Ceramics, The World's Great Collections, vol. 7, Tokyo, 1976, no. 14.