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John Keegan
Sir John Desmond Patrick Keegan was an English military historian, lecturer, author and journalist. He wrote many published works on the nature of combat between prehistory and the 21st century, covering land, air, maritime, intelligence warfare and the psychology of battle.
Excerpt from Wikipedia, available under CC BY-SA 4.0.
Books

La Première guerre mondiale
2005
ISBN 9782262023782
The Mask of Command
1988
ISBN 9780140114065