Hakfman, Robert L. <br/><br/>
Dynamics: Systems: variational methods, and relativity 

 - Massachusetts  Addision Wesley           1962 
 - ix, 355-584 p.  Includes bibliographical reference and index 
 -  Vol. 2 .
<br/><br/><label>Source: </label> Reference  
<br/><br/><label>Subjects--Topical Terms: </label><br/>Variational methods <br/>Mathematics