Edmonds 1993, pp. 371–375, 385–389; Sheffield 2003, pp. 52–54. Edmonds, J. E. (1993) [1932]. Military Operations France and Belgium, 1916: Sir Douglas Haig's Command to the 1st July: Battle of the Somme. History of the Great War Based on Official Documents by Direction of the Historical Section of the Committee of Imperial Defence. Vol. I (facs. repr. Imperial War Museum and Battery Press ed.). London: Macmillan. ISBN978-0-89839-185-5. Sheffield, G. (2003). The Somme. London: Cassell. ISBN978-0-304-36649-1.
Edmonds 1993, p. 483; Sheffield 2003, p. 68. Edmonds, J. E. (1993) [1932]. Military Operations France and Belgium, 1916: Sir Douglas Haig's Command to the 1st July: Battle of the Somme. History of the Great War Based on Official Documents by Direction of the Historical Section of the Committee of Imperial Defence. Vol. I (facs. repr. Imperial War Museum and Battery Press ed.). London: Macmillan. ISBN978-0-89839-185-5. Sheffield, G. (2003). The Somme. London: Cassell. ISBN978-0-304-36649-1.