1. Stability and periodicity of difference equations with finite delay;Elaydi;Funkcial. Ekvac.,1994
2. Stability of infinite delay difference systems;Zhang;Nonlinear Analysis, TMA,1994
3. Razumikhin techniques in delay difference systems;Zhang;PanAmerican Math. J.,1993
4. About stability of differential equations with retarded argument;Khusainov,1974
5. Stability of delayed systems of quadratic form;Khusainov;DAN of Ukraine,1994