@article{IVM_1983_12_a13,
     author = {I. O. Koryakov},
     title = {Maximal periodic semigroups of second-order matrices},
     journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika},
     pages = {69--71},
     year = {1983},
     number = {12},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IVM_1983_12_a13/}
}