Chilton, Paul. <br/><br/>
Introducing X.400 /  [Book]. 
Paul A. Chilton.  
 - Manchester :   NCC Publications,   1989. 
 - 147p. :  ill. ;  22 cm. 
<br/><br/> Includes index. 
<br/><br/><label>ISBN: </label>0850126924 (pbk) 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Digital communications.
<br/><br/><label>Subjects--Index Terms: </label>Digital communication systems