Voir la notice de l'article provenant de la source Math-Net.Ru
@article{IVM_1972_8_a7, author = {Z. I. Kozlova}, title = {$Z_N$-classification, and approximation of sets}, journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika}, pages = {60--69}, publisher = {mathdoc}, number = {8}, year = {1972}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/IVM_1972_8_a7/} }
Z. I. Kozlova. $Z_N$-classification, and approximation of sets. Izvestiâ vysših učebnyh zavedenij. Matematika, no. 8 (1972), pp. 60-69. http://geodesic.mathdoc.fr/item/IVM_1972_8_a7/