1. C. Atindogb\'e, {\it Scalar curvature on lightlike hypersurfaces}, Balkan Society of Geometers, Applied Sciences, {\bf 11}(2009), 9-18.
2. C. Atindogbe and K. L. Duggal, {\it Conformal screen on lightlike hypersurfaces}. Int. J. of Pure and Applied Math., {\bf 11(4)}(2004), 421-442.
3. C. Calin, Contributions to geometry of CR-submanifold, Thesis, University of Iasi-Romania, 1998.
4. B. Y. Chen, {\it Finite type submanifolds in pseudo-euclidean spaces and applications}, Kodai Math. J. {\bf 8} (1985), 358-374.
5. B. Y. Chen, {\it Some results of Chern-do carmo-Kobayashi type and the length of second fundamental form}, Indiana University Math. J., {\bf 20}(1971), 1175-1185.