The Canadian Patent Office Record and Register of Copyrights ...
Canada. Patent Office
No. 352,161. Thermionic Amplifier. Amplificateur thermionique. The Canadian Marconi Company, Montreal, Quebec, Canada, assignee of Victor Owen Stokes, Walton-on-Yo". Essex, England, 6th August, 1935. Filed 2nd Mo, 1934. Serial No.