A drawing of Charity of comparable size and technique was sold at Sotheby Mak van Waay, 2 Nov. 1987, lot 13, illustrated, and a Concord from the same series was sold at Sotheby's, London, 1 July 1991, lot 165, illustrated. These drawings and a study of Faith formerly in the collection of A. Châtelet are presumably for an unrecorded series of prints of the Virtues