@article{JLT_2012_22_1_JLT_2012_22_1_a10,
     author = {M. A. Ben Haddou and M. Boucetta and H. Lebzioui },
     title = {Left-invariant {Lorentzian} {Flat} {Metrics} on {Lie} {Groups}},
     journal = {Journal of Lie theory},
     pages = {269--289},
     publisher = {mathdoc},
     volume = {22},
     number = {1},
     year = {2012},
     url = {http://geodesic.mathdoc.fr/item/JLT_2012_22_1_JLT_2012_22_1_a10/}
}