Valkenburg M E Van <br/><br/>
Network analysis 
Valkenburg M E Van 
 -  1989 
 - p.  cm. 
<br/><br/><label>Standard No.: </label>33339 
<br/><br/><label>Source: </label> Textual 
<br/><br/><label>Dewey Class. No.: </label>D66,3, M9;1-;2