@article{IVM_1967_1_a17,
     author = {B. M. Shain},
     title = {Restrictive bisemigroups of mappings},
     journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika},
     pages = {115--121},
     publisher = {mathdoc},
     number = {1},
     year = {1967},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IVM_1967_1_a17/}
}