Heading, John. <br/><br/>
An introduction to phase-integral methods / 
J. Heading M. A 
 - London ;  New York :  Methuen :  Wiley,  c1962 
 - 160 p. :  illus. ;  20 cm. 
 - Methuen's monographs on physical subjects .
 - Methuen's monographs on physical subjects .
<br/><br/>Includes bibliography. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Differential equations, Linear--Numerical solutions.<br/>Integrals.<br/>Mathematical physics.
<br/><br/><label>Dewey Class. No.: </label>517.38  / HEI 1962