Paul Jokelson Collection, New York (the medallions).
D. Tarshis, 'Sulphides: Cameo Incrusted Jewelry', The Society of Jewelry Historians Newsletter, New York, Spring 1992, vol. 13, cover (the Wellington ring).
P. Jokelson and D. Tarshis, Cameo Incrustation: The Great Sulphide Show, The Corning Museum of Glass, New York, 1988, p. 10, no. 11 (the Wellington ring).