Sigband N B <br/><br/>
Communications for management  and business 
Sigband N B; Bell A N 
 - 5 
 - London  London, Scott Foresman  1989 
 - 793p 
<br/><br/><label>ISBN: </label>0-673-38322-9 
<br/><br/><label>Source: </label>Textbook