@Article{BierThem08,
author = {Michel Bierlaire and MichaŽl Th\'emans },
title = {Dealing with singularities in nonlinear unconstrained optimization},
journal = {European Journal of Operational Research},
volume = {196},
number = {1},
pages = {33-42},
doi = {10.1016/j.ejor.2008.02.036},
year = {2009}
}