Plessis,DU.A,L. <br/><br/>
INFORMATION SYSTEMS :  introduction to computer systems. 

 - ed. 
 - pretoria :  university of south africa,  1981. 
 - 319  p. ;    cm. 
<br/><br/>references. 
<br/><br/><label>ISBN: </label> $ 
<br/><br/><label>Subjects--Topical Terms: </label><br/>computer systems.