1. Alekseevskiĭ, D.V., Kimel’fel’d, B.N.: Structure of homogeneous Riemannian spaces with zero Ricci curvature. Funkcional. Anal. i Priložen. 9(2), 5–11 (1975)
2. Apostolov, V., Drăghici, T.: The curvature and the integrability of almost-Kähler manifolds: a survey. In: Eliashberg, Y., Khesin, B., Lalonde, F. (eds.) Symplectic and Contact Topology: Interactions and Perspectives. Fields Institute Communications, vol. 35, pp. 25–53. American Mathematical Society, Providence (2003)
3. Bedulli, L., Vezzoni, L.: The Ricci tensor of SU(3)-manifolds. J. Geom. Phys. 57(4), 1125–1146 (2007)
4. Belgun, F., Moroianu, A.: Nearly Kähler 6-manifolds with reduced holonomy. Ann. Global Anal. Geom. 19(4), 307–319 (2001)
5. Blair, D.E., Ianus, S.: Critical associated metrics on symplectic manifolds. In: DeTurck, D.M. (ed.) Nonlinear Problems in Geometry. Contemporary Mathematics, vol. 51, pp. 23–29. American Mathematical Society, Providence (1986)