@article{VMUMM_2008_4_a1,
     author = {V. V. Ryzhikov},
     title = {Rank, rigidity of factors, and weak closure of measure-preserving $\mathbf{Z}^n$-actions},
     journal = {Vestnik Moskovskogo universiteta. Matematika, mehanika},
     pages = {13--16},
     publisher = {mathdoc},
     number = {4},
     year = {2008},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/VMUMM_2008_4_a1/}
}