In this paper, relationships between the Ricci curvature and the squared mean curvature for integral submanifolds of an $f.p.k.$-space form by a basic inequality, are studied. We show that if an integral submanifold of maximum dimension of an $f.p.k.$-space form satisfies the equality case, then it must be minimal.
"Ricci curvature of integral submanifolds of an $f.p.k.$-space form." Bull. Belg. Math. Soc. Simon Stevin 21 (3) 437 - 453, august 2014. https://doi.org/10.36045/bbms/1407765882