@article{article221484e2,
title   = {Optimizing the packing of cylinders into a rectangular container: a nonlinear approach},
author = {Birgin, Ernesto Julian Goldberg and Ronconi, Débora Pretti and Martinez, Jesus Manuel},
year = {2005},
doi = {10.1016/j.ejor.2003.06.018},
journal   = {European Journal of Operational Research}
}