@article{02161312,
title = {Counting set systems by weight.},
journal = {The Electronic Journal of Combinatorics [electronic only]},
volume = {12},
year = {2005},
zbl = {1065.05016},
language = {en},
url = {http://dml.mathdoc.fr/item/02161312}
}
Klazar, Martin. Counting set systems by weight.. The Electronic Journal of Combinatorics [electronic only], Tome 12 (2005) . http://gdmltest.u-ga.fr/item/02161312/