Constancy of $\phi-$holomorphic scetional curvature in generalized   $g.f.f-$manifolds
  Tanno [6] provided an algebraic characterization in an almost Hermitian manifold to reduce to a space of constant holomorphic sectional curvature, which he later extended for the Sasakian manifolds as well. In this present paper, we generalize the same characterization in generalized $g.f.f-$manifolds. 
Jae Won Lee, Dae Ho Jin
math.DG