1. [1] Baikoussis, C. and Koufogiorgos, T., On a type of contact manifolds, Journal of Geometry, 46(1993),1–9.
2. [2] Baikoussis, Ch., Blair, D. E. and Koufogiorgos, Th., A decomposition of the curvature tensor of a contact manifold satisfying , Mathematics Technical Report, University of Ioanniana, No.204, June 1992.
3. [3] Blair, D. E., Two remarks on contact metric structures, Tohoku Math. J., 29 (1977), 319–324.
4. [4] Blair, D. E. and Chen, H., A classification of 3-dimensional contact metric manifolds with , , Bulletin of the Institute of Mathematics Academia Sinica, 20 (1992), 379–383.
5. [5] Blair, D. E., Kim, J. S. and Tripathi, M. M., On the concircular curvature tensor of a contact metric manifold, J. Korean Math. Soc., 42(5) (2005), 883–892.