[1] Belkhelfa, M., Deszcz, R., Verstraelen, L.: 
Symmetry properties of Sasakian space forms. Soochow J. Math. 31 (2005), 611–616. 
MR 2190204 | 
Zbl 1087.53021[2] Blair, D.E.: 
Contact manifolds in Riemannian geometry. Lecture Notes in Math., Springer–Verlag, Berlin, 1976. 
MR 0467588 | 
Zbl 0319.53026[5] Chaki, M.C., Chaki, B.: 
On pseudosymmetric manifolds admitting a type of semisymmetric connection. Soochow J. Math. 13 (1987), 1–7. 
MR 0924340[9] Defever, F., Deszcz, R., Verstraelen, L., Vrancken, L.: 
On pseudosymmetric spacetimes. J. Math. Phys. 35 (1994), 5908–5921. 
DOI 10.1063/1.530718 | 
MR 1299927[10] Deszcz, R.: 
On Ricci–pseudo–symmetric warped products. Demonstratio Math. 22 (1989), 1053–1065. 
MR 1077121 | 
Zbl 0707.53020[14] Hashimoto, N., Sekizawa, M.: 
Three-dimensional conformally flat pseudo–symmetric spaces of constant type. Arch. Math. (Brno) 36 (2000), 279–286. 
MR 1811172 | 
Zbl 1054.53060[15] Kowalski, O., Sekizawa, M.: 
Local isometry classes of Riemannian 3–manifolds with constant Ricci eigenvalues $\rho _1 = \rho _ 2\ne \rho _ 3$. Arch. Math. (Brno) 32 (1996), 137–145. 
MR 1407345[16] Kowalski, O., Sekizawa, M.: Three–dimensional Riemannian manifolds of c–conullity two. World Scientific (Singapore–New Jersey–London–Hong Kong) (1996), Published as Chapter 11 in Monograph E. Boeckx, O. Kowalski, L. Vanhecke, Riemannian Manifolds of Conullity Two.
[17] Kowalski, O., Sekizawa, M.: 
Pseudo–symmetric spaces of constant type in dimension three–elliptic spaces. Rend. Mat. Appl. (7) 17 (1997), 477–512. 
MR 1608724 | 
Zbl 0889.53026[18] Kowalski, O., Sekizawa, M.: 
Pseudo–symmetric spaces of constant type in dimension three–non–elliptic spaces. Bull. Tokyo Gakugei Univ. (4) 50 (1998), 1–28. 
MR 1656076 | 
Zbl 0945.53020[21] Özgür, C.: On Kenmotsu manifolds satisfying certain pseudosymmetric conditions. World Appl. Sci. J. 1 (2006), 144–149.
[22] Papantoniou, B.J.: 
Contact Riemannian manifolds satifying $R(\xi , X)\cdot R = 0$ and $ \xi \in (\kappa , \mu )$–nullity distribution. Yokohama Math. J. 40 (1993), 149–161. 
MR 1216349[23] Prakasha, D.G., Bagewadi, C.S., Basavarajappa, N.S.: 
On pseudosymmetric Lorentzian $\alpha $–Sasakian manifolds. Int. J. Pure Appl. Math. 48 (2008), 57–65. 
MR 2456434 | 
Zbl 1155.53019[24] Szabó, Z.I.: 
Structure theorems on Riemannian manifolds satisfying $R(X,Y)\cdot R=0$. I. The local version. J. Differential Geom. 17 (1982), 531–582. 
DOI 10.4310/jdg/1214437486 | 
MR 0683165[25] Szabó, Z.I.: 
Structure theorems on Riemannian manifolds satisfying $R(X,Y)\cdot R=0$. II. Global versions. Geom. Dedicata 19 (1) (1985), 65–108. 
DOI 10.1007/BF00233102 | 
MR 0797152