1. Centrifugal force—a few surprises;Abramowicz;Mon. Not. R. Astron. Soc.,1990
2. Totally umbilic Lorentzian submanifolds;Ahn;J. Korean Math. Soc.,1996
3. The geometry of photon surfaces;Claudel;J. Math. Phys.,2001
4. Lightlike Submanifolds of Semi-Riemannian Manifolds and Applications;Duggal,1996
5. Inertial forces and photon surfaces in arbitrary spacetimes;Foertsch;Classical Quantum Gravity,2003