@article{DM_2009_21_4_a8,
     author = {A. M. Magomedov},
     title = {Defragmentation of permutation tables with four columns},
     journal = {Diskretnaya Matematika},
     pages = {95--104},
     publisher = {mathdoc},
     volume = {21},
     number = {4},
     year = {2009},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DM_2009_21_4_a8/}
}