@article{10.30755/NSJOM.05090,
     author = {Fortun\'e Massamba and Samuel Ssekajja},
     title = { A new approach to totally umbilical null submanifolds},
     journal = {Novi Sad Journal of Mathematics},
     pages = {63 - 76},
     publisher = {mathdoc},
     volume = {47},
     number = {2},
     year = {2017},
     doi = {10.30755/NSJOM.05090},
     url = {http://geodesic.mathdoc.fr/articles/10.30755/NSJOM.05090/}
}