Cf. Dr. J. Chompret, op. cit., figs. 914 & 917 for examples attributed to Siena and Tjark Hausmann, Majolika, Kataloge des Kunstgewerbemuseums Berlin, no 145 and Jörg Rasmussen, Italian Majolica in the Robert Lehman Collection, no. 35 for examples given to Deruta and for details of related examples of the 'petal back' group