@article{KUIPM_1981_9_9_a17,
     author = {E. L. Stolov},
     title = {Semigroups of automata with a two-letter output alphabet},
     journal = {Issledovaniya po Prikladnoi Matematike i Informatike},
     pages = {119--124},
     year = {1981},
     volume = {9},
     number = {9},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/KUIPM_1981_9_9_a17/}
}