[1] DeTurck, D., Koiso, N.: 
Uniqueness and non-existence of metrics with prescribed Ricci curvature.  Annales de l’Institut Henri Poincare (C) Analyse non lineaire 1, 5 (1984), 351–359. 
MR 0779873 | 
Zbl 0556.53026[2] Hamilton, R. S.: 
The Ricci curvature equation.  Lecture notes: Seminar on nonlinear partial differential equations, Mathematical Sciences Research Institute Publications, Berkeley, 1983, 47–72. 
MR 0765228[3] Becce, A. L.: 
Einstein manifolds.  Springer-Verlag, Berlin–Heidelberg, 1987. 
MR 0867684[5] Stepanov, S., Tsyganok, I.: 
Vanishing theorems for projective and harmonic mappings.  Journal of Geometry 106, 3 (2015), 640–641. 
MR 1878047[6] Yano, K., Bochner, S.: 
Curvature and Betti numbers.  Princeton Univ. Press, Princeton, 1953. 
MR 0062505 | 
Zbl 0051.39402[8] Schoen, R., Yau, S. T.: 
Harmonic maps and topology of stable hypersurfaces and manifolds with non-negative Ricci curvature.  Commenttarii Mathematici Helvetici 51, 1 (1976), 333–341. 
DOI 10.1007/BF02568161 | 
MR 0438388[10] Yau, S. T.: 
Seminar on Differential Geometry.  Annals of Mathematics Studies, 102, Princeton Univ. Press, Princeton, NJ, 1982. 
MR 0645728 | 
Zbl 0471.00020[11] Berger, M., Ebin, D.: 
Some decompositions of the space of symmetric tensors on a Riemannian manifold.  Journal of Differential Geometry 3, 3-4 (1969), 379–392. 
DOI 10.4310/jdg/1214429060 | 
MR 0266084[12] Pigola, S., Rigoli, M., Setti, A. G.: 
Vanishing and finiteness results in geometric analysis. A generalization of the Bochner technique.  Birkhäuser, Basel, 2008. 
MR 2401291 | 
Zbl 1150.53001