1. G. A. Bliss, Lectures on the Calculus of Variations, University of Chicago Press, Chicago, Illinois (1946).
2. M. R. Hestenes, Calculus of Variations and Optimal Control Theory, John Wiley and Sons, New York (1966).
3. L. S. Pontryagin, V. G. Boltyanskii, R. V. Gamkrelidze, and E. F. Mishchenko, The Mathematical Theory of Optimal Processes, John Wiley and Sons (Interscience Publishers), New York (1962).
4. A. Miele, R. E. Pritchard, and J. N. Damoulakis, Sequential gradient-restoration algorithm for optimal control problems, J. Optim. Theory Appl.
5, 235–282 (1970).
5. A. Miele, J. N. Damoulakis, J. R. Cloutier, and J. L. Tietze, Sequential gradientrestoration algorithm for optimal control problems with nondifferential constraints, J. Optim. Theory Appl.
13, 218–255 (1974).