@article{GDZPPN00223517X, title = {When is a Ring of Torus Invariants a Polynomial Ring?}, journal = {Manuscripta mathematica}, volume = {83}, year = {1994}, pages = {161-170}, zbl = {0809.14008}, url = {http://dml.mathdoc.fr/item/GDZPPN00223517X} }
Wehlau, David L. When is a Ring of Torus Invariants a Polynomial Ring?. Manuscripta mathematica, Tome 83 (1994) pp. 161-170. http://gdmltest.u-ga.fr/item/GDZPPN00223517X/