Ore, Oystein <br/><br/>
The four-color problem  / 

 - New York:  Academic Press,  1968 
 - xv, 259p. Index 
 - Pure and Applied Mathematics, v. 27 .
<br/><br/> "Discusses the methods in graph theory that have been developed in the last century" 
<br/><br/><label>Dewey Class. No.: </label>511.5  / Or66.FC