@article{VMUMM_1984_1_a3,
     author = {Yu. A. Khashina},
     title = {Schreier varieties of $n$-semigroups},
     journal = {Vestnik Moskovskogo universiteta. Matematika, mehanika},
     pages = {17--21},
     year = {1984},
     number = {1},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/VMUMM_1984_1_a3/}
}