Haiyang Gao, Z. J. Wang and H. T. Huynh. (2013). Differential Formulation of Discontinuous Galerkin and Related Methods for the Navier-Stokes Equations.
            <i>Communications in Computational Physics</i>. <i>13</i> (4).
            1013-1044.
         doi:10.4208/cicp.020611.090312a