@article{JLT_2019_29_2_JLT_2019_29_2_a4,
     author = {P. Tirao and S. Vera},
     title = {There are {No} {Rigid} {Filiform} {Lie} {Algebras} of {Low} {Dimension}},
     journal = {Journal of Lie theory},
     pages = {391--412},
     year = {2019},
     volume = {29},
     number = {2},
     url = {http://geodesic.mathdoc.fr/item/JLT_2019_29_2_JLT_2019_29_2_a4/}
}