1. Colin Adams, The non-compact hyperbolic 3-manifold of minimal volume,Proc. Amer. Math. Soc. 100 (1987), 601–606.
2. Colin Adams, SNAPPEA: The Weeks hyperbolic 3-man- ifolds program,Notices of the Amer. Math. Soc. 37 (1990), 273–275.
3. M. F. Atiyah, V. K. Patodi, and I. M. Singer, Spectral asymmetry and Riemannian geometry: I,Math. Proc. Camb. Phil. Soc. 77 (1975), 43–69.
4. M. F. Atiyah, V. K. Patodi, and I. M. Singer, Spectral asymmetry and Riemannian geometry: II,Math Proc. Camb. Phil. Soc. 78 (1975), 405–432.
5. Donald Blackett,Elementary Topology, New York: Academic Press (1967).