On Coincidence Points of Maps from Manifolds to Spheres Tammo DieckLarry Smith Indiana University Mathematics Journal 1979 text pdf 10.1512/iumj.1979.28.28017 10.1512/iumj.1979.28.28017 en Indiana Univ. Math. J. 28 (1979) 251 - 255 state-of-the-art mathematics http://iumj.org/access/