Lehoczky, Sandor <br/><br/>
Art of problem solving. 2V  V2 : And beyond 

 - Ed. 7 
 - California  AOPS Incorporated  2006 
 - 296p;  
<br/><br/><label>ISBN: </label>977304582 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Mathematics -- Problem solving<br/>Problem solving -- Mathematics