@article{01522332,
title = {Counting set covers and split graphs.},
journal = {Journal of Integer Sequences [electronic only]},
volume = {3},
year = {2000},
zbl = {0953.05033},
language = {en},
url = {http://dml.mathdoc.fr/item/01522332}
}
Royle, Gordon F. Counting set covers and split graphs.. Journal of Integer Sequences [electronic only], Tome 3 (2000) . http://gdmltest.u-ga.fr/item/01522332/