@article{TDM_2001_4_a13,
     author = {V. N. Sachkov},
     title = {Partitions with merging and discordant set partitions},
     journal = {Trudy po diskretnoj matematike},
     pages = {201--222},
     publisher = {mathdoc},
     volume = {4},
     year = {2001},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TDM_2001_4_a13/}
}