BAINOV, D. D., KOSTADINOV, S. I., MINH, N. V. and ZABREIKO, P. P. (1994) “A TOPOLOGICAL CLASSIFICATION OF DIFFERENTIAL EQUATIONS WITH IMPULSE EFFECT”, Tamkang Journal of Mathematics, 25(1), pp. 15–27. doi: 10.5556/j.tkjm.25.1994.4420.