@article{01428675,
title = {M\"obius invariants for pairs of spheres },
journal = {Beitr\"age zur Algebra und Geometrie},
volume = {41},
year = {2000},
pages = {233-246},
zbl = {1003.53016},
language = {en},
url = {http://dml.mathdoc.fr/item/01428675}
}
Sulanke, Rolf. Möbius invariants for pairs of spheres . Beiträge zur Algebra und Geometrie, Tome 41 (2000) pp. 233-246. http://gdmltest.u-ga.fr/item/01428675/