APA
Keegan J., . (2001). War and our world. New York: Vintage Books.
Chicago
Keegan John, . 2001. War and our world. New York: Vintage Books.
Harvard
Keegan J., . (2001). War and our world. New York: Vintage Books.
MLA
Keegan John, . War and our world. New York: Vintage Books. 2001.