Encyclopedia of information systems and services / 
ed. by Anthony T. Kruzas and John Schmittroth, Ji. 
 - 2nd ed 
 -  Gale Research,  c1981. 
 - xiii, 933 p ;  29 cm. 
<br/><br/><label>ISBN: </label>0810309424 
<br/><br/><label>Universal Decimal Class. No.: </label>002.5(03)