On Vitali's Theorem for Complex Spaces with Singularities R. Gunning Indiana University Mathematics Journal 1959 text pdf 10.1512/iumj.1959.8.58009 10.1512/iumj.1959.8.58009 en Indiana Univ. Math. J. 8 (1959) 133 - 141 state-of-the-art mathematics http://iumj.org/access/