Extended Asymptotic Eigenvalue Distributions for Bounded Domains in n-Space F. Brownell Indiana University Mathematics Journal 1957 text pdf 10.1512/iumj.1957.6.56006 10.1512/iumj.1957.6.56006 en Indiana Univ. Math. J. 6 (1957) 119 - 166 state-of-the-art mathematics http://iumj.org/access/