A Wiener-Levy Theorem for Quotients, with Applications to Volterra Equations Kenneth Hannsgen Indiana University Mathematics Journal 1980 text pdf 10.1512/iumj.1980.29.29008 10.1512/iumj.1980.29.29008 en Indiana Univ. Math. J. 29 (1980) 103 - 120 state-of-the-art mathematics http://iumj.org/access/