Voir la notice de l'article provenant de la source Math-Net.Ru
@article{MZM_1999_65_6_a10, author = {S. A. Shapovalov}, title = {The depth invariant for group actions on countable phase spaces}, journal = {Matemati\v{c}eskie zametki}, pages = {893--907}, publisher = {mathdoc}, volume = {65}, number = {6}, year = {1999}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/MZM_1999_65_6_a10/} }
S. A. Shapovalov. The depth invariant for group actions on countable phase spaces. Matematičeskie zametki, Tome 65 (1999) no. 6, pp. 893-907. http://geodesic.mathdoc.fr/item/MZM_1999_65_6_a10/