Statistical Reference to Casualty and Other Figures, 1618–1991; 593,000: John Keegan The Second World War (1989); 593,000: J. A. S. Grenville citing "official
Blitzkrieg in the West. London: Chevron/Ian Allen, 2007. ISBN 978-1-85780-272-6. Keegan, John. The Second World War. New York: Viking Penguin, 1989. ISBN 0-670-82359-7