“…Hence, for solving QAPs in practice, existing approaches either resort to (expensive) branch and bound methods [6], or to approximations, e.g. based on spectral methods [35,18], dual decomposition [57], linear relaxations [54,55], convex relaxations [71,46,23,22,30,1,21,7], path following [70,72,29], or alternating directions [33].…”