Discrete mathematics : 
L. Lovasz ; J. Pelikan ; K. Vesztergombi 
 - New York :  Springer,  2003 
 - ix, 290 p. :  ill. ;  25 cm. 
 - Undergraduate texts in mathematics .
<br/><br/> Includes index. 
<br/><br/><label>ISBN: </label>0387955844 (acid-free paper) | 8181280652