1. Digital and Sampled-data Control Systems;Tou,1959
2. Optimum Design of Digital Control Systems;Tou,1963
3. Nonlinear Techniques for Improving Servo Performance;McDonald,1950
4. Optimal Discontinuous Forcing Terms;Bushaw,1958
5. On the Bang-bang Control Problem;Bellman;Quart. Jour. Appl. Math.,1956