Initial-Value Problems for Pseudo-Parabolic Partial Differential Equations V. Gopala RaoTsuan Ting Indiana University Mathematics Journal 1974 text pdf 10.1512/iumj.1974.23.23011 10.1512/iumj.1974.23.23011 en Indiana Univ. Math. J. 23 (1974) 131 - 153 state-of-the-art mathematics http://iumj.org/access/