@article{article38018cf9,
title   = {New and improved results for packing identical unitary radius circles within triangles, rectangles and strips},
author = {Birgin, Ernesto Julian Goldberg and Gentil, J. Marcel},
year = {2010},
doi = {10.1016/j.cor.2009.09.017},
journal   = {Computers & Operations Research}
}