Solution of the Dirichlet Problem for the Ellipse by Interpolating Harmonic Polynomials J. Walsh Indiana University Mathematics Journal 1960 text pdf 10.1512/iumj.1960.9.59011 10.1512/iumj.1960.9.59011 en Indiana Univ. Math. J. 9 (1960) 193 - 196 state-of-the-art mathematics http://iumj.org/access/