@article{10_5427_jsing_2014_10j,
     author = {Shyuichi Izumiya and Takami Sato},
     title = {Lightlike hypersurfaces along spacelike submanifolds in de {Sitter} space},
     journal = {Journal of Singularities},
     pages = {157--173},
     publisher = {mathdoc},
     volume = {10},
     year = {2014},
     doi = {10.5427/jsing.2014.10j},
     url = {http://geodesic.mathdoc.fr/articles/10.5427/jsing.2014.10j/}
}