@article{IVM_1996_4_a2,
     author = {A. Yu. Baryshnikov and A. B. Livchak},
     title = {The languages ${\rm PQL}$ and ${\rm FO}+{\rm LFP}$ are equivalent even without the presence of order},
     journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika},
     pages = {18--23},
     publisher = {mathdoc},
     number = {4},
     year = {1996},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IVM_1996_4_a2/}
}