@article{01016572,
title = {Hopf-bifurcation in systems with spherical symmetry. I: Invariant tori.},
journal = {Documenta Mathematica},
volume = {2},
year = {1997},
pages = {61-113},
zbl = {0873.58020},
language = {en},
url = {http://dml.mathdoc.fr/item/01016572}
}
Leis, Christian. Hopf-bifurcation in systems with spherical symmetry. I: Invariant tori.. Documenta Mathematica, Tome 2 (1997) pp. 61-113. http://gdmltest.u-ga.fr/item/01016572/