Fraenkel, L.E <br/><br/>
Introduction to maximum principles & symmetry in elliptic problems 
L.E. Fraenkel 
 - Cambridge  Cambridge University Press  2000 
 - x  340 
 - Cambridge tracts in mathematics 128 .
<br/><br/><label>ISBN: </label>9780521461955 
<br/><br/><label>Dewey Class. No.: </label>10.03  / FRAE