Edmonds 1991, p. 325; Prior & Wilson 1996, p. 160. Edmonds, J. E. (1991) [1948]. Military Operations France and Belgium 1917: 7 June–10 November Messines and Third Ypres (Passchendaele). History of the Great War Based on Official Documents by Direction of the Historical Section of the Committee of Imperial Defence. Vol. II (Imperial War Museum and Battery Press ed.). London: HMSO. ISBN978-0-89839-166-4. Prior, R.; Wilson, T. (1996). Passchendaele: The Untold Story. Yale University Press. ISBN978-0-300-06692-0.
Edmonds 1991, pp. 325–326, 316; Beach 2005, p. 222. Edmonds, J. E. (1991) [1948]. Military Operations France and Belgium 1917: 7 June–10 November Messines and Third Ypres (Passchendaele). History of the Great War Based on Official Documents by Direction of the Historical Section of the Committee of Imperial Defence. Vol. II (Imperial War Museum and Battery Press ed.). London: HMSO. ISBN978-0-89839-166-4. Beach, J. (2005). British Intelligence and the German Army 1914–1918 (PhD). London University. OCLC500051492. Retrieved 19 July 2014.
Edmonds 1991, pp. 325–326, 316; Beach 2005, p. 222. Edmonds, J. E. (1991) [1948]. Military Operations France and Belgium 1917: 7 June–10 November Messines and Third Ypres (Passchendaele). History of the Great War Based on Official Documents by Direction of the Historical Section of the Committee of Imperial Defence. Vol. II (Imperial War Museum and Battery Press ed.). London: HMSO. ISBN978-0-89839-166-4. Beach, J. (2005). British Intelligence and the German Army 1914–1918 (PhD). London University. OCLC500051492. Retrieved 19 July 2014.