@article{01990002, title = {Composite covering systems of minimum cardinality.}, journal = {Integers}, volume = {3}, year = {2003}, zbl = {1028.11006}, language = {en}, url = {http://dml.mathdoc.fr/item/01990002} }
Jenkin, Scott; Simpson, Jamie. Composite covering systems of minimum cardinality.. Integers, Tome 3 (2003) . http://gdmltest.u-ga.fr/item/01990002/