Jun-ichi Inoguchi, Kazuhiro Okumura. Remarks on Ricci tensor fields of contact metric manifolds. Journal of Geometry. 2025. 116. 2
Kazuhiro Okumura. A behavior of the structure tensor on real hypersurfaces in a nonflat complex space form. Scientiae Mathematicae Japonicae. 2022. 85. 1. 49-57
Kazuhiro Okumura. Real hypersurfaces in a nonflat complex space form whose certain tensor is recurrent. Journal of Geometry. 2022. 113. 3
Kazuhiro Okumura. Real hypersurfaces in a nonflat complex space form whose ⁎-Ricci tensor is D-recurrent. Differential Geometry and its Applications. 2021. 78. 101780-101780
Kazuhiro Okumura. A certain η-parallelism on real hypersurfaces in a nonflat complex space form. Mathematica Slovaca. 2021. 71. 6. 1553-1564