The Melnikov Method and Elliptic Equations with Critical Exponent R. JohnsonXingbin PanYingfei Yi Indiana University Mathematics Journal 1994 text pdf 10.1512/iumj.1994.43.43046 10.1512/iumj.1994.43.43046 en Indiana Univ. Math. J. 43 (1994) 1045 - 1077 state-of-the-art mathematics http://iumj.org/access/