Juan Zhang, Jiabin Song & Huanzhen Chen. (2023). A Priori Error Estimates for Spectral Galerkin Approximations of Integral State-Constrained Fractional Optimal Control Problems.
            <i>Advances in Applied Mathematics and Mechanics</i>. <i>15</i> (3).
            568-582.
         doi:10.4208/aamm.OA-2021-0251