@article{10_4153_CMB_1989_041_8,
     author = {Asperti, A. C. and Dajczer, M.},
     title = {Conformally {Flat} {Riemannian} {Manifolds} as {Hypersurfaces} of the {Light} {Cone}},
     journal = {Canadian mathematical bulletin},
     pages = {281--285},
     year = {1989},
     volume = {32},
     number = {3},
     doi = {10.4153/CMB-1989-041-8},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CMB-1989-041-8/}
}