@article{DCG_1995__13_3-4_131377,
     author = {P.M. Gruber},
     title = {A {Helmholtz-Lie} {Type} {Characterization} of {Ellipsoids,} {I} .},
     journal = {Discrete & computational geometry},
     pages = {517--528},
     publisher = {mathdoc},
     volume = {13},
     number = {3-4},
     year = {1995},
     zbl = {0824.52006},
     url = {http://geodesic.mathdoc.fr/item/DCG_1995__13_3-4_131377/}
}