Singh, Omprakash. <br/><br/>
Sanchar ke mool sidhanth 

 - New Delhi  Classical Publishing Company  2012 
 - 400p. 
<br/><br/><label>ISBN: </label> RS 750.00 
<br/><br/><label>Source: </label> RS 750.00 
<br/><br/><label>Dewey Class. No.: </label>302.2 SIN