@article{GDZPPN00036424X, title = {Penny-Packing and Two-Dimensional Codes.}, journal = {Discrete \& computational geometry}, volume = {5}, year = {1990}, pages = {1-12}, zbl = {0686.52010}, url = {http://dml.mathdoc.fr/item/GDZPPN00036424X} }
Sloane, N.J.A.; Graham, R.L. Penny-Packing and Two-Dimensional Codes.. Discrete & computational geometry, Tome 5 (1990) pp. 1-12. http://gdmltest.u-ga.fr/item/GDZPPN00036424X/