1. Amiri, Α./ Pirkul, Η.
(1997): New formulation and relaxation to solve a concavecost network flow problem. In: Journal of the Operational Research Society 48, 278–287
2. Aykin T.
(1994): Lagrangian relaxation based approaches to capacited hub-and-spoke network design problem. In: European Journal of Operational Research 79, 501–523
3. Balakrishnan Α./ Graves S. C.
(1989): A Composite Algorithm for a Concave-Cost Network Flow Problem. In: Networks 19, 175–202
4. Working Paper;C Barnhart,1996
5. Bazlamacci C.F./ Hindi K.F.
(1996): Enhanced Adjacent Extreme-point Search and Tabu Search for the Minimum concave-cost Uncapacitated Transshipment Problem. In: Journal of the Operational Research Society 47, 1150–1165