Gustafson, Karl E. <br/><br/>
Introduction to partial differential equations and Hilbert space methods / 
Karl E. Gustafson. 
 - 3rd ed. 
 - Mineola :  Dover,  1999. 
 - XV, 448 p. :  fig. ;  21 cm. 
<br/><br/>Index pp. 436-448 
<br/><br/><label>ISBN: </label>0-486-61271-6 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Differential equations, Partial<br/>Hilbert space