Outline of radio / 
R. S. Elven. ...[et al.]. 
 - London :  George Newnes,  c 1949. 
 - 688 p. :  ill. ;  22 cm. 
<br/><br/> Includes index. 
<br/><br/>19  19 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Radio .
<br/><br/><label>Dewey Class. No.: </label>621.3843 / O94