1. The Mathematical Theory of Optimal Processes;Pontryagin,1969
2. Asymptotic Methods of Optimal Control;Akulenko,1987
3. An optimal control which minimizes the extremum of a function of phase coordinates;Kuznetsov;Kibernetika,1968
4. Introduction to Functional Analysis;Vulikh,1967
5. Functional Analysis and Computational Mathematics;Kollatz,1969