@ARTICLE{Absi2011a,
author={Absi, Nabil and Kedad-Sidhoum, Safia and Dauz{\`e}re-P{\'e}r{\`e}s, St{\'e}phane},
title = {Uncapacitated lot-sizing problem with production time windows, early
production, backlog and lost sale},
journal = {International Journal of Production Research},
year = {2011},
volume = {49},
pages = {2551--2566},
number = {9},
url = {ENSMSE_CMP_WP2009_10.pdf},
doi = {http://dx.doi.org/10.1080/00207543.2010.532920}
}