Letter from Magritte to Mariën, 1938, in Magritte, Destination, no. 5. Letter from Magritte to Mariën, August 1938, in Magritte, Destination, no. 9. Letter from Magritte to Mariën, December 1939, in Magritte, Destination, no. 23. Letter from Magritte to Mariën, December 1939, in Magritte, Destination, no. 24. Letter from Magritte to Mariën, January 1940, in Magritte, Destination, no. 28. Letter from Magritte to Mariën, Ferbuary 1940, in Magritte, Destination, no. 30. M. Mariën, 'Le Plagiat', in L'Invention collective, Brussels, 1940. M. Mariën, L'Oiseau qui n'a qu'une aile, Antwerp, 1941, (illustrated on the frontispiece). 'Surrealism in Belgium' in View, New York, 1946, (illustrated on the cover). D. Sylvester & S. Whitfield, René Magritte, Catalogue Raisonné, vol. II, Oil Paintings and Objects 1931-1948, Antwerp, 1993, no. 472, p. 276 (illustrated). S. Gohr, Magritte. Attempting the Impossible, Paris, 2009, no. 322, p. 235 (illustrated). D. Sylvester, Magritte, Brussels, 2009, p. 319 & 431 (illustrated p. 318). R. Hughes, Magritte en poche, London, 2009, p. 198 (illustrated).