Discontinuity Relations for Charged, Compressible, Relativistic Fluids N. Coburn Indiana University Mathematics Journal 1961 text pdf 10.1512/iumj.1961.10.10023 10.1512/iumj.1961.10.10023 en Indiana Univ. Math. J. 10 (1961) 361 - 391 state-of-the-art mathematics http://iumj.org/access/