1. Mathematical Aspects of Control Theory;Bellman,1956
2. The Mathematical Theory of Optimal Process;Pontryagin,1962
3. A general solution for linear sampled data control;Gunckel;ASME J. Basic Eng.,1963
4. On linear control theory;Joseph;AIEE Trans. (Appl. Ind.),1961
5. Optimum Design of Digital Control Systems;Tou,1963