@article{JIS_2004__7_1_a5,
     author = {Kilibarda,  Goran and Jovovi\'c,  Vladeta},
     title = {Antichains of multisets},
     journal = {Journal of integer sequences},
     year = {2004},
     volume = {7},
     number = {1},
     zbl = {1071.06001},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/JIS_2004__7_1_a5/}
}