J. Richard, I. de Farias Jr., and G. Nemhauser. Combinatorial Optimization, volume 2570 of Lecture Notes in Computer Science, page 158-170. Springer, (2001)
M. Ball, C. Barnhart, G. Nemhauser, and A. Odoni. Transportation, volume 14 of Handbooks in Operations Research and Management Science, Elsevier, (2007)