@article{AIHPA_1973__18_1_77_0,
     author = {Robson, E. H.},
     title = {Null hypersurfaces in general relativity theory},
     journal = {Annales de l'institut Henri Poincar\'e. Section A, Physique Th\'eorique},
     pages = {77--88},
     publisher = {Gauthier-Villars},
     volume = {18},
     number = {1},
     year = {1973},
     mrnumber = {327255},
     language = {en},
     url = {http://archive.numdam.org/item/AIHPA_1973__18_1_77_0/}
}