@article{GDZPPN002316633, title = {Symmetry Properties of Singularities of C$^\circ$$^\circ$-Functions.}, journal = {Mathematische Annalen}, volume = {237}, year = {1978}, pages = {147-156}, zbl = {0384.58011}, url = {http://dml.mathdoc.fr/item/GDZPPN002316633} }
Jänich, Klaus. Symmetry Properties of Singularities of C°°-Functions.. Mathematische Annalen, Tome 237 (1978) pp. 147-156. http://gdmltest.u-ga.fr/item/GDZPPN002316633/