Optimizing Cost Flows by Modifying Arc Costs and Capacities. - Ingo Demgensky; Hartmut Noltemeier; Hans-Christoph Wirth (WG, 2000)

On the flow cost lowering problem. - Ingo Demgensky; Hartmut Noltemeier; Hans-Christoph Wirth (Eur. J. Oper. Res., 2002)

Optimizing cost flows by edge cost and capacity upgrade. - Ingo Demgensky; Hartmut Noltemeier; Hans-Christoph Wirth (J. Discrete Algorithms, 2004)