@article{CRMATH_2013__351_7-8_303_0,
     author = {Abbena, Elsa and Garbiero, Sergio and Salamon, Simon},
     title = {Bach-flat {Lie} groups in dimension 4},
     journal = {Comptes Rendus. Math\'ematique},
     pages = {303--306},
     publisher = {Elsevier},
     volume = {351},
     number = {7-8},
     year = {2013},
     doi = {10.1016/j.crma.2013.04.011},
     language = {en},
     url = {http://www.numdam.org/articles/10.1016/j.crma.2013.04.011/}
}