1. A. M. Samoilenko and N. A. Perestyuk, Impulsive Differential Equations [in Russian], Vyshcha Shkola, Kiev (1987).
2. A. A. Boichuk, N. A. Perestyuk, and A. M. Samoilenko, “Periodic solutions of impulsive differential systems of integrodifferential equations in the critical cases,” Differents. Uravn., No. 9, 1516–1521 (1991).
3. A. A. Boichuk, Constructive Methods for the Analysis of Boundary-Value Problems [in Russian], Naukova Dumka, Kiev (1990).
4. A. A. Boichuk and R. F. Khrashchevskaya, "Weakly nonlinear boundary-value problems for differential systems with pulse influence," Ukr. Mat. Zh., bf 45, No. 2, 221-225 (1993)
5. English translation: Ukr. Math. J., 45, No. 2, 235-240 (1993).