Handbook for Radio Operators :  Working Installations Licensed By The Home Office. 

 - 4th Ed. 
 - London :  HER MAJESTY'S STATIONERY OFFICE,  1975. 
 - ix, 257 p. 
<br/><br/><label>ISBN: </label>0118804626 
<br/><br/><label>Dewey Class. No.: </label>621.3845  / HAN