1. J. P. Alexander, G. C. Hamrick, and J. W. Vick, Involutions on homotopy spheres, (in preparation).
2. W. Browder, Surgery on Simply Connected Manifolds, Springer-Verlag, Berlin and New York, 1972.
3. F. Hirzebruch. Differentiable manifolds and quadratic forms, Mimeographed notes, University of California, Berkeley, 1962.
4. M. Kervaire and J. Milnor, Groups of homotopy spheres, I, Annals of Math. 77 (1963), 504–537.
5. J. Milnor, Differentiable manifolds which are homotopy spheres, Mimeographed notes, Princeton, 1958.