A Non-Linear Hypersonic Shock Problem Derek Naylor Indiana University Mathematics Journal 1962 text pdf 10.1512/iumj.1962.11.11038 10.1512/iumj.1962.11.11038 en Indiana Univ. Math. J. 11 (1962) 691 - 702 state-of-the-art mathematics http://iumj.org/access/