Template:Browder1970
From Manifold Atlas
W. Browder, Free -actions on homotopy spheres, Topology of Manifolds (Proc. Inst., Univ. of Georgia, Athens, Ga., 1969), Markham, Chicago, Ill. (1970), 217–226. MR0276982 (43 #2720) Zbl 0284.57030