1. R. Bellman and K.L. Cooke, Differential Difference Equations, New York, Academic Press, 1963.
2. K.L. Cooke and J.M. Ferreira, “Stability conditions for linear retarded functional differential equations”, J. Math. Anal. Appl., 96(1983), 480–504.
3. K.L. Cooke and Z. Grossman, “Discrete delay, distributed delay and stability switches”, J. Math. Anal. Appl. 86 (1982), 592–627.
4. K.L. Cooke and P. van den Driessche, “On zeroes of some transcendental equations”, in preparation.
5. H.I. Freedman and V.S.H. Rao, “The tradeoff between mutual interference and time lags in predator-prey systems”, preprint.