On a Cardinality-Constrained Transportation Problem With Market Choice
  It is well-known that the intersection of the matching polytope with a cardinality constraint is integral [8]. We prove a similar result for the polytope corresponding to the transportation problem with market choice (TPMC) (introduced in [4]) when the demands are in the set $\{1,2\}$. This result generalizes the result regarding the matching polytope and also implies that some special classes of minimum weight perfect matching problem with a cardinality constraint on a subset of edges can be solved in polynomial time. 
Pelin Damci-Kurt, Santanu S. Dey, Simge Kucukyavuz
math.OC cs.DS