Compare the very similar ewer, with cover, in the collection of The Art Institute, Chicago, illustrated by M. Medley, Yüan Porcelain and Stoneware, London, 1974, pl. 10, and later sold in these rooms, 9 November 1978, lot 125, from the Collection of Mr. and Mrs. Otto Doering, Snr. This type has been dated to the first quarter of the 14th century, and according to Medley, "the slip appears to have been roughly applied to conform broadly in outline with the proposed elements and has been tidied up with some careful tool work".
Another example, with elaborate detailing, is illustrated in Sekai toji zenshu, Tokyo, 1981, vol. 13, p. 56, no. 42.