Hancock C.  John. <br/><br/>
An introduction to the principles of communication theory  [Book /] 
John.C Hancock . 
 - New York :  Tata McGraw-Hill,  1974. 
 - 253 p :  ill ;  22 cm . 
<br/><br/><label>ISBN: </label>0070993416 
<br/><br/><label>Dewey Class. No.: </label>621.382