1. Critical graphs, matchings and tours or a hierarchy of relaxations for the travelling salesman problem;Cornuéjols,1981
2. Paths, trees and flowers;Edmonds;Canadian J. Math.,1965
3. Computers and Intractability. A Guide to the Theory of NP-Completeness;Garey,1979
4. Dynamic matchings and quasi-dynamic fractional matchings;Orlin,1982
5. Facets of 1-matching polyhedra;Pulleyblank,1974