Grete Jalk, Dansk Møbelkunst gennem 40 aar, Vol. 1 1927-1936, Copenhagen, 1987, pp. 117, fig. 1, 157, fig. 2 and p. 259 for a similar example; Grete Jalk, Dansk Møbelkunst gennem 40 aar, Vol. 2 1937-1946, Copenhagen, 1987, p. 11, fig. 2 and p. 85, fig. 1 for a similar example;Tina Jørstian and Poul Eric Munk Nielsen, eds., Light Years Ahead, The Story of the PH Lamp, Copenhagen, 1994, p. 189 for a similar example; Charlotte and Peter Fiell, eds., 1000 Lights, Vol. 1: 1879 to 1959, Cologne, 2005, p. 312 for a similar example