Digraphs/  theory,algorithms and applications 
Bang-Jensen,Jorgen 
 - 2nd ed. 
 - New York:  Springer,  2001. 
 - 795 p. 
<br/><br/><label>ISBN: </label>9780857290410 
<br/><br/><label>Dewey Class. No.: </label>511.54  / BAN/D