Spacelike maximal surfaces with constant scalar normal curvature in a normal contact Lorentzian manifold. Toshihiko, Ikawa — 1998 Bulletin of the Malaysian Mathematical Society. Second Series
Jacobi fields and its application of normal contact Lorentzian manifolds. Toshihiko, Ikawa — 2000 Bulletin of the Malaysian Mathematical Sciences Society. Second Series
On some C-totally real submanifolds in a space with Sasakian 3-structure Toshihiko Ikawa — 1984 Colloquium Mathematicae
Sasakian manifolds with vanishing contact Bochner curvature tensor and constant scalar curvature Toshihiko Ikawa; Masahiro Kon — 1977 Colloquium Mathematicae