Fagen, M. D. (1978). A history of engineering and science in the bell system: National service in war and peace (1925-1975). United States of American: Bell Telephone Laboratories, Inc.

Fagen, M. D. A History of Engineering and Science in the Bell System: National Service in War and Peace (1925-1975). United States of American: Bell Telephone Laboratories, Inc, 1978.

Fagen, M. D. A History of Engineering and Science in the Bell System: National Service in War and Peace (1925-1975). United States of American: Bell Telephone Laboratories, Inc, 1978.