1. M. Anderson, Ricci curvature bounds and Einstein metrics on compact manifolds, preprint.
2. Self-duality in four dimensional Riemannian geometry;Atiyah;Proc. Roy. Soc. London Ser. A,1978
3. Spectral asymmetry and riemannian geometry. I;Atiyah;Math. Proc. Cambridge Philos. Soc.,1975
4. II, Math. Proc. Cambridge Philos. Soc., 78 (1975), 405–432.
5. The mass of an asymptotically flat manifold;Bartnik;Comm. Pure and Appl. Math.,1986