On Mixed Problems for the Nonlinear Heat Equation M. George Indiana University Mathematics Journal 1962 text pdf 10.1512/iumj.1962.11.11045 10.1512/iumj.1962.11.11045 en Indiana Univ. Math. J. 11 (1962) 851 - 858 state-of-the-art mathematics http://iumj.org/access/