Cf. Barracca, Jader, Negretti, Giampiero and Nencini, Franco, Les Temps de Cartier, Wrist International S.r.l., Milan, 1989, p.40 and Chaille, Francois and Cologni, Franco, The Cartier Collection - Timepieces, Flammarion, Paris, 2006, p.308 & 309 for clocks of a similar design