Extreme Eigenvalues of Toeplitz Operators of the Hankel Type I James Davis Indiana University Mathematics Journal 1965 text pdf 10.1512/iumj.1965.14.14018 10.1512/iumj.1965.14.14018 en Indiana Univ. Math. J. 14 (1965) 245 - 275 state-of-the-art mathematics http://iumj.org/access/