Marcel Turkensteen Diptesh Ghosh Boris Goldengorin Gerard Sierksma Iterative patching and the asymmetric traveling salesman problem. 63-77 2006 3 Discrete Optimization 1 http://dx.doi.org/10.1016/j.disopt.2005.10.005 db/journals/disopt/disopt3.html#TurkensteenGGS06