On Isolated Singularities in Some Nonlinear Partial Differential Equations Patricio Aviles Indiana University Mathematics Journal 1983 text pdf 10.1512/iumj.1983.32.32051 10.1512/iumj.1983.32.32051 en Indiana Univ. Math. J. 32 (1983) 773 - 791 state-of-the-art mathematics http://iumj.org/access/