Fiber Bundles with Discrete Singular Set J. Timourian Indiana University Mathematics Journal 1969 text pdf 10.1512/iumj.1969.18.18007 10.1512/iumj.1969.18.18007 en Indiana Univ. Math. J. 18 (1969) 61 - 70 state-of-the-art mathematics http://iumj.org/access/