@article{GDZPPN002083221, title = {Densest Packing of Six Equal Circles in a Square.}, journal = {Elemente der Mathematik}, volume = {49}, year = {1994}, pages = {27-31}, zbl = {0807.52013}, url = {http://dml.mathdoc.fr/item/GDZPPN002083221} }
Melissen, Hans. Densest Packing of Six Equal Circles in a Square.. Elemente der Mathematik, Tome 49 (1994) pp. 27-31. http://gdmltest.u-ga.fr/item/GDZPPN002083221/