Elsgolts, L. E. (Lev Ernestovich) <br/><br/>
Calculus of variations. 

 - London : Reading, MA :  London : Reading, MA :  Pergamon Press ; Addison-Wesley,  Pergamon Press ; Addison-Wesley,  1962, [c1961] 
 - ADIWES international series in mathematics .
<br/><br/><label>Subjects--Topical Terms: </label><br/>Calculus of variations.