@article{IVM_1988_1_a11,
     author = {A. V. Tishchenko},
     title = {The degree of principal left simplicity of a~semigroup},
     journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika},
     pages = {79--83},
     publisher = {mathdoc},
     number = {1},
     year = {1988},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IVM_1988_1_a11/}
}