@article{MAN_1980__252_163454,
     author = {Wim H. Hesselink},
     title = {Characters of the {Nullcone.}},
     journal = {Mathematische Annalen},
     pages = {179--182},
     publisher = {mathdoc},
     volume = {252},
     year = {1980},
     zbl = {0447.17006},
     url = {http://geodesic.mathdoc.fr/item/MAN_1980__252_163454/}
}