Ratzan, Lee <br/><br/>
Understanding information systems :  what they do and why we need them / 
Lee Ratzan 
 - New Delhi :  Indiana Publishing House,  2009 
 - xvi, 253 p. :  ill. ;  26 cm. 
<br/><br/>Includes bibliographical references (p. 237-245) and index 
<br/><br/><label>ISBN: </label>9788184082388  RM177.61 818408238X 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Information science<br/>Information storage and retrieval systems<br/>Computer science--Popular works<br/>Mathematics--Popular works