Saaty, Thomas L. <br/><br/>
The four color problem:  assaults and conquest. 
Thomas L. Saaty 
 - New York:  Dover Publications,  1986. 
 - v, 217p. 
<br/><br/><label>Subjects--Index Terms: </label>The four color problem. 
<br/><br/><label>Universal Decimal Class. No.: </label>519.17  / SAA