@article{IM_1992__108_2_143997,
     author = {S. Berman and R.V. Moody},
     title = {Lie algebras graded by finite root systems and the intersection matrix algebras of {Slodowy.}},
     journal = {Inventiones mathematicae},
     pages = {323--348},
     publisher = {mathdoc},
     volume = {108},
     number = {2},
     year = {1992},
     zbl = {0778.17018},
     url = {http://geodesic.mathdoc.fr/item/IM_1992__108_2_143997/}
}