1. Angell, T.S.: Existence of optimal control without convexity and a bang-bang theorem for linear Volterra equations. J. Optim. Theory Appl. 19(1), 63–79 (1976)
2. Bressan, A.: Extremal solutions to differential inclusions via Baire category: a dual approach. J. Differ. Equ. 255, 2392–2399 (2013)
3. Bressan, A., Mazzola, M., Nguyen, Khai T.: The bang-bang theorem via Baire category. A dual approach. NoDEA Nonlinear Differ. Equ. Appl. 23(4), 23–46 (2016)
4. Cellina, A.: On the differential inclusion
$$x^{\prime }\in [-1,1]$$
x
′
∈
[
-
1
,
1
]
. Atti Accad. Naz. Lincei Rend. Cl. Sci. Fis. Mat. Natur. 69, 1–6 (1980)
5. Cesari, L.: Optimization - Theory and Applications. Problems with Ordinary Differential Equations. Springer, New York (1983)