1. Y.P. Aneja, R. Chandrasekaran and K.P.K. Nair, “Classes of linear programs with integral optimal solutions,”Mathematical Programming Study 25 (1985) 225–237.
2. W.W. Bein, “Netflows, polymatroids, and greedy structures,” Ph.D. Thesis, Universität Osnabrück (Osnabrück, Germany, 1986).
3. W.W. Bein and P. Brucker, “Greedy concepts for network flow problems,”Discrete Applied Mathematics 15 (1986) 135–144.
4. W.W. Bein, P. Brucker and A. Tamir, “Minimum cost flow algorithms for series parallel networks,”Discrete Applied Mathematics 10 (1985) 117–124.
5. P.C. Gilmore, E.L. Lawler and D.B. Shmoys, “Well-solved special cases,” in: E.L. Lawler, J.K. Lenstra, A.H.G. Rinnooy Kan and D.B. Shmoys, eds.,The Travelling Salesman Problem — A Guided Tour of Combinatorial Optimization (Wiley, New York, 1985) pp. 87–143.