Huygens' principle and hyperbolic equations / 
by Günther, Paul, 
 - Boston :  Academic Press,  1988 
 - lvii, 847 p. ;  24 cm. 
 - Perspectives in mathematics ;  vol. 5 .
<br/><br/> Includes index. 
<br/><br/><label>ISBN: </label>123073308