@article{GDZPPN002361981, title = {The spectrum associated to a radical operation.}, journal = {Mathematica Scandinavica}, volume = {73}, year = {1993}, pages = {5-14}, zbl = {0790.14001}, url = {http://dml.mathdoc.fr/item/GDZPPN002361981} }
Ernström, Lars. The spectrum associated to a radical operation.. Mathematica Scandinavica, Tome 73 (1993) pp. 5-14. http://gdmltest.u-ga.fr/item/GDZPPN002361981/