Source: https://www.researchgate.net/profile/Jerome-Monnot/publication/48444966_Le_voyageur_de_commerce_et_ses_variations_un_tour_d'horizon_de_ses_resolution/links/0c96052a841f6e0fe9000000/Le-voyageur-de-commerce-et-ses-variations-un-tour-dhorizon-de-ses-resolution.pdf