@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/