@article{MAN_1994__298_2_165178,
     author = {Karl Heinrich Hofmann and W.A.F. Ruppert},
     title = {On porcupine varieties in {Lie} algebras.},
     journal = {Mathematische Annalen},
     pages = {403--426},
     publisher = {mathdoc},
     volume = {298},
     number = {2},
     year = {1994},
     zbl = {0791.17007},
     url = {http://geodesic.mathdoc.fr/item/MAN_1994__298_2_165178/}
}