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• [1] D.E. Blair, Contact manifolds in Riemannian geometry, Lecture Notes in Mathematics, 509 Springer-Verlag, Berlin, 1976.
• [2] D.E. Blair, Riemannian geometry of contact and symplectic manifolds, Progress in Math., Birkhauser, Boston, 2002.
• [3] D.E. Blair, Two remarks on contact metric structures, Tohoku Math. J., 29, 1977, 319-324.
• [4] D.E. Blair, T. Koufogiorgos and B.J. Papantoniou, Contact metric manifolds satisfying a nullity condition, Israel J. Math., 91, 1995, 189-214.
• [5] D.E. Blair, J.S. Kim and M.M. Tripathi, On the concircular curvature tensor of a contact metric manifold, J. Korean Math. Soc., 42(5), 2005, 883-992.
• [6] E. Cartan, Surune classe remarquable despaces de Riema, Bulletin de la Soc. Math., France, 54, 1926, 214-264.
• [7] M.C. Chaki, On conformally flat Pseudo-Ricci Symmetric Manifolds, Period. Math. Hungar., 19, 1988, 209-215.
• [8] M.C. Chaki, On pseudosymmetric manifolds, An. Stiint. Univ., Al. I. Cuza Iasi, 33, 1987, 53-58.
• [9] M.C. Chaki, On pseudo Ricci symmetric manifolds, Bulg. J. Phys. 15, 1988, 526-531.
• [10] A. De, C-Bochner Curvature Tensor on N(k)-Contact Metric Manifolds, Lobachevskii Journal of Mathematics, 31(3), 2010, 209-214.
• [11] U.C. De, N. Guha and D. Kamilya, On generalized Ricci-recurrent manifolds, Tensor (NS), 56, 1995, 312-317.
• [12] U.C. De and S. Bandyopadhyay, On weakly symmetric Riemannian spaces, Publ. Math. Debrecen, 54, 1999, 377-381.
• [13] U.C. De and P. Majhi, On a Type of Contact Metric Manifolds, Lobachevskii Journal of Mathematics, 34(1), 2013, 89-98.
• [14] R. Deszcz, On pseudosymmetric spaces, Acta Math., Hungarica, 53, 1992, 185-190.
• [15] J.A. Oubina, New classes of contact metric structures, Publ. Math. Debrecen., 32, 1985, 187-193.
• [16] E.M. Patterson, Some theorems on Ricci-recurrent spaces, J Lond Math Soc., 27, 1952, 287-295.
• [17] Rajendra Prasad, Vibha Srivastava and Shyam Kishor, On generalized Ricci-recurrent N(k)-contact metric manifods, Journal of National Academy of Mathematics, India.
• [18] S. Sasaki, Lecture Note on almost Contact Manifolds, Part I, Tohoku Univ., Tohoku 1965.
• [19] S. Sasaki, Lecture Note on almost Contact Manifolds, Part II, Tohoku Univ., Tohoku 1967.
• [20] A. Selberg, Harmonic analysis and discontinuous groups in weakly symmetric Riemannian spaces with applications to dirichlet series, Indian Math. Soc., 20, 1956, 47-87.
• [21] Z.I. Szabo, Structure theorems on Riemannian spaces satisfying R(X, Y) . R = 0. I, The local version, J. Differential Geom., 17(4), 1982, 531-582.
• [22] L. Tamassy and T.Q. Binh, On weakly symmetric and weakly projective symmetric Rimannian manifolds, Coll. Math. Soc., J. Bolyai, 50, 1989, 663-670.
• [23] L. Tamassy and T.Q. Binh, On weak symmetries of Einstein and Sasakian manifolds, Tensor, N. S., 53, 1993, 140-148.
• [24] S. Tanno, The automorphism groups of almost contact Riemannian manifolds, Tohoku Math. J., 21, 1969, 21-38.
• [25] S. Tanno, Ricci curvature of contact Riemannian manifolds, Tohoku Math. J., 40, 1988, 441-448.
• [26] M. Tarafdar, On Pseudo Symmetric and Pseudo Ricci Symmetric Sasakian manifolds, Per. Math. Hung. 22(2), 1991, 125-129.
• [27] M. Tarafdar and U.C. De, On pseudo symmetric and pseudo ricci symmetric K-contact manifolds, Per. Math. Hung. 31(1), 1995, 21-25.
• [28] M. Tarafdar, On Pseudo Symmetric and Pseudo Ricci Symmetric P-Sasakian manifolds, Analele Stiintifice ale Universitatii Al. I. Cuza din Iasi. Serie Noua. Matematica, 37(2), 1991.
• [29] Venkatesha and R.T. Naveen Kumar, Qausi conformal curvature tensor on N(k)-contact metric manifolds, Acta Math. Univ. Comenianae, LXXXV(1), 2016, 125-134.
• [30] K. Yano, Concircular geometry I. Concircular transformations, Proc. Imp. Acad. Tokyo, 16, 1940, 195-200.
• [31] A.A. Walker, On Ruses spaces of recurrent curvature, Proc. London Math. Soc., 52, 1950, 36-64.