Asymptotic wave theory  
Roseau, Maurice. 
 - Amsterdam : | New York :  North-Holland Pub. Co. ; | American Elsevier Pub. Co.,  1976 
 - x, 349 p.  ill. ;  23 cm. 
<br/><br/> Includes index. 
<br/><br/><label>ISBN: </label>0444107983 (American Elsevier)