@article{BMMS_1998_21_1_a3,
     author = {Bhagwat Prasad},
     title = {Semi-Invariant
                        {Submanifolds} of a {Lorentzian} {Para-Sasakian} {Manifold}},
     journal = {Bulletin of the Malaysian Mathematical Society},
     year = {1998},
     volume = {21},
     number = {1},
     url = {http://geodesic.mathdoc.fr/item/BMMS_1998_21_1_a3/}
}