@article{IVM_2000_5_a5,
     author = {N. Kehayopulu and M. Tsingelis},
     title = {A~remark on congruences in ordered semigroups},
     journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika},
     pages = {37--39},
     publisher = {mathdoc},
     number = {5},
     year = {2000},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IVM_2000_5_a5/}
}