Sanchar ke mool siddhant 
Om Prakash Singh 
 - New Delhi  Lokbharati Prakashan  2018 
 - 303p. 
<br/><br/><label>ISBN: </label>978-93-86863-61-4  Rs.650.00 
<br/><br/><label>Dewey Class. No.: </label>891.438  / S617