Troutman, J.L <br/><br/>
Variational calculus with elementary convexity 
J.L. Troutman 
 - New York  Springer  1983 
 - xiv  364 
 - Undergraduate texts in mathematics .
<br/><br/><label>ISBN: </label>3540907718 
<br/><br/><label>Dewey Class. No.: </label>4.13  / TROU