@article{MZM_1980_28_2_a8,
     author = {N. P. Korovina},
     title = {Systems of pairs of cyclic type},
     journal = {Matemati\v{c}eskie zametki},
     pages = {271--278},
     publisher = {mathdoc},
     volume = {28},
     number = {2},
     year = {1980},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_1980_28_2_a8/}
}