Elements of discrete mathematics 
Liu, C. L. 
 - 2nd ed. 
 - New York :  McGraw-Hill,  1985 
 - xiv, 433 p. :  ill. ;  25 cm. 
 - McGraw-Hill computer science series | McGraw-Hill series in computer organization and architecture .
<br/><br/><label>ISBN: </label>007038133X : | 0071005447