[1] R. Bellman and K.L. Cooke: Differential-difference equations, Academic Press, New York-London, 1963.
[2] D. Breda: On characteristic roots and stability charts of delay differential equations, Internat. J. Robust Nonlinear Control 22 (2012), 892–917.
[3] S.A. Campbell: Delay independent stability for additive neural networks, Differential Equations Dynam. Systems 9 (2001), 115–138.
[4] S.A. Campbell: Stability and bifurcation of a simple neural network with multiple time delays, Fields Inst. Commun. 21 (1999), 65–79.
[5] H.I. Freedman and Y. Kuang: Stability switches in linear scalar neutral delay equations, Funkcial. Ekvac. 34 (1991), 187–209.
[6] M. Funakubo, T. Hara and S. Sakata: On the uniform asymptotic stability for a linear integro-differential equation of Volterra type, J. Math. Anal. Appl. 324 (2006), 1036–1049.
[7] J.K. Hale: Theory of Functional Differential Equations, Applied Mathematics Sciences 3, Springer-Verlag, New York-Heidelberg, 1977.
[8] J.K. Hale and S.M. Verduyn Lunel: Introduction to functional differential equations, Applied Mathematical Sciences 99, Springer-Verlag, New York, 1993.
[9] N.D. Hayes: Roots of the transcendental equation associated with a certain difference-differential equation, J. London Math. Soc. 25 (1950), 226–232.
[10] Y. Kiri and Y. Ueda: Stability criteria for some system of delay differential equations; in Theory, Numerics and Applications of Hyperbolic Problems. II, 137–144, Springer Proc. Math. Stat. 237, Springer, Cham, 2018.
[11] Y. Kuang: Delay differential equations with applications in population dynamics, Academic Press, Boston, 1993.
[12] Z. Lu and W. Wang: Global stability for two-species Lotka-Volterra systems with delay, J. Math. Anal. Appl. 208 (1997), 277-280.
[13] H. Matsunaga: Stability switches in a system of linear differential equations with diagonal delay, Appl. Math. Comput. 212 (2009), 145–152.
[14] H. Matsunaga and H. Hashimoto: Asymptotic stability and stability switches in a linear integro-differential system, Differ. Equ. Appl. 3 (2011), 43–55.
[15] H. Matsunaga and M. Suzuki: Effect of off-diagonal delay on the asymptotic stability for an integro- differential system, Appl. Math. Lett. 25 (2012), 1744–1749.
[16] S. Nakaoka, Y. Saito and Y. Takeuchi: Stability, delay, and chaotic behavior in a Lotka-Volterra predator- prey system, Math. Biosci. Eng. 3 (2006), 173–187.
[17] J. Nishiguchi: On parameter dependence of exponential stability of equilibrium solutions in differential equations with a single constant delay, Discrete Contin. Dyn. Syst. 36 (2016), 5657–5679.
[18] G. Orosz, R.E. Wilson and G. Ste´pa´n: Traflc jams: dynamics and control, Philos. Trans. R. Soc. Lond. Ser. A Math. Phys. Eng. Sci. 368 (2010), 4455–4479.
[19] M.R. Roussel: The use of delay differential equations in chemical kinetics, J. Phys. Chem. 100 (1996), 8323–8330.
[20] S. Ruan: Absolute stability, conditional stability and bifurcation in Kolmogorov-type predator-prey systems with discrete delays, Quart. Appl. Math. 59 (2001), 159–173.
[21] M. Suzuki and H. Matsunaga: Stability criteria for a class of linear differential equations with off-diagonal delays, Discrete Contin. Dyn. Syst. 24 (2009), 1381–1391.
[22] J. Wei and C. Zhang: Stability analysis in a first-order complex differential equations with delay, Nonlinear Anal. 59 (2004), 657–671.