@article{IVM_1995_1_a3,
     author = {I. Yu. Zhil'tsov},
     title = {Unary operations on pseudovarieties of semigroups},
     journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika},
     pages = {45--52},
     publisher = {mathdoc},
     number = {1},
     year = {1995},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IVM_1995_1_a3/}
}