Yang Yang, Yanfang Lei & Zhiyong Si. (1970). Unconditional Stability and Error Estimates of the Modified Characteristics FEM for the Time-Dependent Viscoelastic Oldroyd Flows.
            <i>Advances in Applied Mathematics and Mechanics</i>. <i>13</i> (2).
            311-332.
         doi:10.4208/aamm.OA-2018-0169