Title: Spy Overhead
Author: Clinch Calkins
Calkins, Clinch (1937, 1965, 1971). Spy Overhead: The Story of Industrial Espionage. New York: Arno
- Labor unions–United States.
- Business intelligence–United States.
- Industrial relations–United States.
- Espionage–United States.
Date Posted: July 28, 2016
Reviewed by Paul W. Blackstock and Frank L. Schaf
This is an account of a special part of industrial espionage—labor spying. In Spy Overhead the author describes how industrialists, by hiring secret operatives to spy among workmen, attempted to prevent American labor from organizing itself; Calkins based her study and analyses on material obtained from the records of Senator La Follette’s civil liberties investigative committee.
 Blackstock, Paul W. (1978) and Frank L. Schaf, Jr. Intelligence, Espionage, Counterespionage, And Covert Operations: A Guide to Information Sources. Detroit: Gale Research Co., p. 134