Variational methods in optimization Donald R. Smith. Smith, Donald R. (Donald Ray), 1939 January 23- Mathematical optimization. Calculus of variations. QA402.5 .S55 515.64 SMV Includes bibliographical references. Englewood Cliffs, N.J., Prentice-Hall 1974. 1974. 1974 Text xv, 378 p. : eng