Harary, Frank. <br/><br/>
Structural models :   an introduction to the theory of directed graphs / 
by Frank Harary, Robert Z. Norman and Dorwin Cartwright. 
 - New York :  Wiley,  1965. 
 - ix, 415 p. :    illu. ;  24 cm. 
<br/><br/> Includes glossary and index. 
<br/><br/><label>ISBN: </label>9780471351306 (hbk.) 047135130X (hbk.) 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Mathematical models.
<br/><br/><label>Dewey Class. No.: </label>511.5  / HAR/S