Keyfitz,Barbara Lee <br/><br/>
Nonlinear evolution equations that change type / 
Keyfitz,Barbara Lee. 
 - New York:  Springer,  1990. 
 - xiv,284p;25cm 
<br/><br/>Includes bibliographical references. 
<br/><br/><label>ISBN: </label>0387973532 
<br/><br/><label>Dewey Class. No.: </label>515.353 KEY