@article{articlefe816fb0,
title   = {A variational theory for hight rays on Lorentz manifolds},
author = {Giannoni, Fabio and Masiell, Antonio and Piccione, Paolo},
year = {1997},
doi = {10.1016/s0764-4442(97)87893-7},
journal   = {Comptes Rendus de l'Académie des Sciences - Series I - Mathematics}
}