The railway signal dictionary ; an illustrated vocabulary of terms which designate American railway signals, their parts, attachments and details of construction, with descriptions of methods of operation and some illustrations of British signals and practice
Railway Signal Association; Adams, Braman B. (Braman Blanchard), b. 1851; Hitt, Rodney, 1882-; Cloud, Arthur David, 1884-; Simmons, Harold Hoyt, 1888-