@article{GDZPPN002475707, title = {Extremal Packing and Covering Sets.}, journal = {Monatshefte f\"ur Mathematik}, volume = {71}, year = {1967}, pages = {203-213}, zbl = {0256.52013}, url = {http://dml.mathdoc.fr/item/GDZPPN002475707} }
Hans, Rajinder Jeet. Extremal Packing and Covering Sets.. Monatshefte für Mathematik, Tome 71 (1967) pp. 203-213. http://gdmltest.u-ga.fr/item/GDZPPN002475707/