@article{DM_1991_3_1_a1,
     author = {L. A. Pomortsev},
     title = {Combinatorial-symmetric analysis of multidimensional random walks},
     journal = {Diskretnaya Matematika},
     pages = {21--41},
     publisher = {mathdoc},
     volume = {3},
     number = {1},
     year = {1991},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DM_1991_3_1_a1/}
}