References
- Connections, Curvature and Cogomology v.Ⅱ W. Greub;S. Halperin;R. Vanstone
- Foundation of Differential Geometry v.Ⅰ S. Kobayshi;K. Nomizu
- J. of Diff. Geom. v.7 A condition for paracompactness of a manifold K. B. Marathe
- Semi-Riemannian Geometry B. O'Neill
- Differential Geometry of Complex Hypersurfaces in Indefinite Complex space Forms v.3 A. Romero;Y. J. Suh(ed.)
- Bull. London Math. Soc. v.28 An Integral Inequality on compact Lorenz Manifolds, and Its Applications A. Romero;M. Sanchez
- Differential Geometry v.Ⅱ M. Spivak