@article{DM_2011_23_1_a5,
     author = {V. L. Shcherbina},
     title = {A case of insolubility of the problem of equivalence of programs},
     journal = {Diskretnaya Matematika},
     pages = {72--83},
     publisher = {mathdoc},
     volume = {23},
     number = {1},
     year = {2011},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DM_2011_23_1_a5/}
}