Heading, John <br/><br/>
An introduction to phase-integral methods / 
John Heading 
 - London :  Methuen,  1962 
 - 160 p. :  ill. ;  20 cm. 
 - Methuen's monographs on physical subjects .
<br/><br/>Includes bibliographical references and index 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Differential equations, Linear--Numerical solutions<br/>Integrals
<br/><br/><label>Dewey Class. No.: </label>517.38