@article{EJDE_2006__2006__a5,
     author = {Luisi,  Valeria},
     title = {Light rays in static spacetimes with critical asymptotic behavior: a variational approach},
     journal = {Electronic journal of differential equations},
     year = {2006},
     volume = {2006},
     zbl = {1112.53055},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/EJDE_2006__2006__a5/}
}