@TechReport{BierBurtThir89,
author = {Michel Bierlaire and Didier Burton and Suzanne Thiry },
title = {Le contournement de Couvin: \'etude pr\'eliminaire},
institution = {Ecole Polytechnique F\'ed\'erale de Lausanne},
number = {FUNDP, TRG 89/11},
year = {1989}
}