Wei , Gongming and Dong , Jing. (2015). Existence and Uniqueness of the Global Smooth Solution to the Periodic Boundary Value Problem of Fractional Nonlinear Schrödinger System.
            <i>Journal of Partial Differential Equations</i>. <i>28</i> (2).
            95-119.
         doi:10.4208/jpde.v28.n2.1