@article{AM2_1991__41_2-3_137405,
     author = {J.B. Wilker and M. Paluszny},
     title = {A case of the 3-dimensional problem of {Appollonius.}},
     journal = {Aequationes mathematicae},
     pages = {172--186},
     publisher = {mathdoc},
     volume = {41},
     number = {2-3},
     year = {1991},
     zbl = {0739.51014},
     url = {http://geodesic.mathdoc.fr/item/AM2_1991__41_2-3_137405/}
}