Luca Forlizzi Juraj Hromkovic Guido Proietti Sebastian Seibert On the Stability of Approximation for Hamiltonian Path Problems. 2006 1 Algorithmic Operations Research 1 http://journals.hil.unb.ca/index.php/AOR/article/view/95 db/journals/aor/aor1.html#ForlizziHPS06