Unique solutions of 2 X 2 conservation laws with large data Alberto BressanRinaldo Colombo Indiana University Mathematics Journal 1995 text pdf 10.1512/iumj.1995.44.2004 10.1512/iumj.1995.44.2004 en Indiana Univ. Math. J. 44 (1995) 677 - 726 state-of-the-art mathematics http://iumj.org/access/