1. On the existence and boundedness of solutions of non-linear differential-difference equations;Bellman;Ann. Math. (Princeton),1949
2. Stability theory and adjoint operators for linear differential-difference equations;Bellman;Trans. AMS,1959
3. Asymptotic behavior of solutions of differential-difference equations;Bellman;Mem. AMS,1959
4. Bellman, R., and Cooke, K. L., “Differential-Difference Equations.” Academic Press, New York, in press.
5. Non-linear delay differential equations;Brownell,1950