==References=====Bibliography===* Sobel, Robert "The Entrepreneurs: Explorations Within the American Business Tradition" (Weybright & Talley 1974), chapter 8, Donald Douglas: The Fortunes of War ISBN 0-679-40064-8.
* Robert Sobel, "The Entrepreneurs: Explorations Within the American Business Tradition" (Weybright & Talley 1974), chapter 8, Donald Douglas: The Fortunes of War ISBN 0-679-40064-8.