We show that there is no $CR$ submanifold with semi-flat normal connection and with recurrent Ricci tensor in a complex space form of nonzero constant holomorphic sectional curvature, if the dimension of its holomorphic distribution is greater than 2.
"Ricci Recurrent $CR$ Submanifolds of a Complex Space Form." Tsukuba J. Math. 31 (2) 233 - 252, December 2007. https://doi.org/10.21099/tkbjm/1496165146