@article{DAN_1969_189_5_a2,
     author = {P. P. Zabreiko and A. V. Zafievskii},
     title = {A certain class of semigroups},
     journal = {Doklady Akademii Nauk},
     pages = {934--937},
     publisher = {mathdoc},
     volume = {189},
     number = {5},
     year = {1969},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1969_189_5_a2/}
}