@article{DAN_1961_138_1_a19,
     author = {L. N. Shevrin},
     title = {Structural properties of semigroups},
     journal = {Doklady Akademii Nauk},
     pages = {73--76},
     publisher = {mathdoc},
     volume = {138},
     number = {1},
     year = {1961},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1961_138_1_a19/}
}