@article{deKPS08,
  title = "On semidefinite programming relaxations of the traveling salesman problem",
  author = "E. De Klerk and D.V. Pasechnik and R. Sotirov",
  year = "2008",
  journal = "SIAM Journal on Optimization",
  note = "Preprint 2007-12-1858 at Optimization online",
  pages = "1559--1573",
  volume = "19",
}