Ullman, Jeffrey D <br/><br/>
Principles of Database Systems / 
by Jeffrey D. Ullman  
 - 2nd Ed. 
 - New Delhi:  Galgotia Publications,  1997 
 - p.484 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Computer Science<br/>Computer Programming
<br/><br/><label>Dewey Class. No.: </label>005.74  / ULL-P2