1. J. L. Lions, Optimal control of distributed systems, Springer, 1971 (Dunod, 1968)
2. J. L. Lions, Report at the I.M. Congress, Vancouver, 1974.
3. A. Bensoussan and J. L. Lions, C. R. Acad. Sc. Paris, 276 (1973), 1411–1415, and paper in Applicable Analysis, 1974.
4. A. Bensoussan and J. L. Lions, C. R. Acad. Sc. Paris, 276 (1973), 1189–1192 and 1333–1338.
5. A. Bensoussan and J. L. Lions, C. R. Acad. Sc. Paris, 278 (1974), 675–679, 747–751, 1345–1349.