Dunkan, L. Rudolph. <br/><br/>
Radio telegraphy and telephony/ 
Rudolph L. Duncan and Charles E. Drew 
 - 2nd ed. 
 - London  Chapman and Hall Ltd.  c1931 
 - xi,1046p.:  23 cm. 
<br/><br/> Includes index. 
<br/><br/>
<br/><br/><br/>English. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Radio<br/>Wireless electronics
<br/><br/><label>Dewey Class. No.: </label>621.3841DUR