Boundary Values of Solutions of Elliptic Equations Richard Saylor Indiana University Mathematics Journal 1975 text pdf 10.1512/iumj.1975.24.24075 10.1512/iumj.1975.24.24075 en Indiana Univ. Math. J. 24 (1975) 907 - 913 state-of-the-art mathematics http://iumj.org/access/