A very similar single monkey in the Mottahedeh Collection was illustrated by Howard and Ayers, op. cit., p. 594, and sold Sotheby's New York 19 October 2000. Two other singles from the Copeland Collection are illustrated by Sargent, op. cit., p. 176-6, who cites a fruther single from the Ionides Collection; a pair from the Garbisch Collection was sold by Sotheby's at Pokety Farms, 22 May 1980, lot 277.