Data and circuits of radio receiver and amplifier valves, 2nd supplement   
ed. by N.S. Markus, Otte J. 
 -  Philips Tech.Lib.  1952 
 - Electronic valve series book III A. .
<br/><br/><label>Dewey Class. No.: </label>621.384132  / N49.2 "SER" "R"