1. Functional equations in the theory of dynamic programming—V: Positivity and quasilinearity;Bellman,1955
2. Adaptive Control Processes: A Guided Tour;Bellman,1961
3. F. Calogero. “Variable Phase Approach to Potential Scattering.” Academic Press, New York, to appear.
4. A note on asymptotic behavior of differential equations;Bellman;Boll. UMI,1963
5. On nonlinear differential equations, the maximum operation, and monotone convergence;Kalaba;J. Math. Mech.,,1959