1. BARROS, M. and ROMERO, A., Indefinite Kähler manifolds, Math. Ann.,261 (1982), 55?62.
2. BONOME, A., CASTRO, R., GARCIA-RIO, E. and HERVELLA, L.M., On the holomorphic sectional curvature of an indefinite Kähler manifold, C. R. Acad. Sci. Paris,315 (1992), 1183?1187.
3. BONOME, A., CASTRO, R., GARCIA-RIO, E., HERVELLA, L.M. and MATSUSHITA, Y., Null holomorphically flat indefinite almost Hermitian manifolds, Illinois J. Math.,39 (1995), to appear.
4. CENDAN-VERDES, J., GARCIA-RIO, E. and VAZQUEZ-ABAL, M.E., On the semi-Riemannian structure of the tangent bundle of a two-point homogeneous space, Riv. Mat. Univ. Parma, (5)3 (1994), 253?270.
5. DAJCZER, M. and NOMIZU, K., On sectional curvature of indefinite metrics II, Math. Ann.,247 (1980), 279?282.