1. An improved bound for the critical explosion condition for an exothermic reaction in an arbitrary shape;Wake;Combustion and Flame,1971
2. Some positone problems suggested by nonlinear heat generation;Keller;J. Math. Mech.,1967
3. Boundary problems for certain quasilinear elliptic equations;Hudjaeov;Dokl. Akad. Nauk. SSSR,1964
4. H. B. Keller and J. P. Keener, private communication.