Theory of Shock Waves in Relativistic Magneto-Fluid-Dynamics G. Saini Indiana University Mathematics Journal 1961 text pdf 10.1512/iumj.1961.10.10057 10.1512/iumj.1961.10.10057 en Indiana Univ. Math. J. 10 (1961) 887 - 902 state-of-the-art mathematics http://iumj.org/access/