Stormark, O <br/><br/>
Lie's stuctural approach to PDE systems 
O. Stormark 
 - Cambridge  Cambridge university Press  2000 
 - xv  572  572 
 - Encyclopedia of mathematics 80 .
<br/><br/><label>ISBN: </label>9780521780889 
<br/><br/><label>Dewey Class. No.: </label>10.02  / 10.13 STOR