Technical instruction for marine radio officers : (formerly Handbook of technical instruction for wireless telegraphists) / By H.M. Dowsett and L.E.Q. Walker. Dowsett, H. M. Walker, L. E. Q. Hawkhead, John Clayborough. Telegraph, Wireless. TK5742 .D57 1950 621.384 DOT Includes index. London : Wireless world, c1950. c1950. 1950 Text 699 p. : eng