Compare a similar ewer dated to the first half of the 8th century in the Museum Für Kunst und Gewerbe: Reemtsma Collection, Hamburg, illustrated by W. Watson, Tang and Liao Ceramics, New York, 1984, pl. 71. Compare, also, another example, but with a different glaze pattern, illustrated in Sekai toji zenshu, rev. ed., Tokyo, 1976, vol. 11, pl. 225 and again in Mayuyama, Seventy Years, Tokyo, 1976, vol. 1, pl. 231.