Singnals Royal <br/><br/>
Handbook of line communication 

 -  1957 
 - p.  cm. 
<br/><br/><label>Standard No.: </label>71711 
<br/><br/><label>Source: </label> Textual 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Electrical communication
<br/><br/><label>Dewey Class. No.: </label>D666:4, J7.1