1. Agrawal, O.P.: A general formulation and solution scheme for fractional optimal control problems. Nonlinear Dyn. 38, 323–337 (2004)
2. Agrawal, O.P., Defterli, O., Baleanu, D.: Fractional optimal control problems with several state and control variables. J. Vib. Control 16(13), 1967–1976 (2012)
3. Ali, H.M., Lobo Pereira, F., Gama, S.M.A.: A new approach to the Pontryagin maximum principle for nonlinear fractional optimal control problems. Math. Methods Appl. Sci. 39(13), 3640–3649 (2016)
4. Alsaedi, A., Alghamdi, N., Agrawal, R.P., Ntouyas, S.K., Ahmad, B.: Multi-term fractional-order boundary-value problems with nonlocal integral boundary conditions. Electron. J. Differ. Equ. 2018(87), 1–16 (2018)
5. Bachar, I., Mâagli, H., Rădulescu, V.D.: Positive solutions for superlinear Riemann–Liouville fractional boundary-value problems. Electron. J. Differ. Equ. 2017(240), 1–16 (2017)