Andreescu, Titu  . <br/><br/>
Path to combinatorics for undergraduates : countings strategies /  
by Titu Andreescu, Zuming Feng. 
 - Berlin :   Birkhauser ,   2004 
 - xviii, 228p :  
<br/><br/><label>ISBN: </label>978-0-8176-4288-4 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Combinatorial number theory
<br/><br/><label>Dewey Class. No.: </label>B3  / P4