1. A. A. Abuladze, Optimal Control Problems for Systems Described by Integral Equations [in Russian], Tbilis. Univ., Tbilisi (1988).
2. A. P. Afanas’ev, V. V. Dikusar, A. A. Milyutin, and S. A. Chukanov, Necessary Condition in Optimal Control [in Russian], Nauka, Moscow (1990).
3. A. A. Agrachev and R. V. Gamkrelidze, “Second-order optimality principle for a time-optimal control problem,” Mat. Sb., 100, No. 4, 610–643 (1976).
4. M. Akian, P. Bliman, and M. Sorine, “Control of delay systems with relay,” IMA J. Math. Control Inform., 19, 133–155 (2002).
5. V. M. Alekseev, V. M. Tikhomirov, and S. V. Fomin, Optimal Control [in Russian], Nauka, Moscow (1979).