@article{10_37236_1908,
     author = {Martin Klazar},
     title = {Counting set systems by weight},
     journal = {The electronic journal of combinatorics},
     year = {2005},
     volume = {12},
     doi = {10.37236/1908},
     zbl = {1065.05016},
     url = {http://geodesic.mathdoc.fr/articles/10.37236/1908/}
}