Yang , Yanbing and Huang , Shaobin. (2018). Finite Time Blow Up of Solution for 1-D Nonlinear Wave Equation of Sixth Order with Linear Restoring Force at High Energy Level.
            <i>Journal of Partial Differential Equations</i>. <i>31</i> (3).
            274-280.
         doi:10.4208/jpde.v31.n3.6