Xiuyan Peng & Yi Niu. (2019). Sharp Conditions on Global Existence and Non-Global Existence of Solutions of Cauchy Problem for 1D Generalized Boussinesq Equations..
            <i>Journal of Partial Differential Equations</i>. <i>30</i> (2).
            95-110.
         doi:10.4208/jpde.v30.n2.1