3D.E.Hardt and D.C.Grossard.A variable geometry die for sheet metal forming:design and control ,Joint Automatic Control Conference, San Francisco, California USA,August, 1980.
4D.E.Hardt, B.A.Olsen and B.T.Allison et al., Sheet metal forming with discrete die surfaces, Proc.9th NAMRC, 1981:140-144.
5D.F.Walczyk, D.E.Hardt.Design and analysis of reconfigurable discrete dies for sheet metal forming,Journal of Manufacturing Systems, 1998,17 ( 6 ) :436-454.
6J.M.Papazian.Tools of change:Reconfigurable forming dies raise the efficiency of small-lot production,Mechanical Engineering, 2002,124 ( 2 ) :52-55.
8J.M.Papazian, E.L.Anagostou, R.J.Christ et al.Tooling for rapid sheet metal parts production, 6th Joint FAA/DoD/NASA Conference on Aging Aircraft, San Francisco, CA, USA, Sept., 2002.
9Ming-Zhe Li, Zhong-Yi Cai, Chun-Guo Liu, et al..Recent developments in multi-point forming technology, Proceedings of the 8th International Conference on Technology of Plasticity, Edizioni Progetto Padova, Verona, Italy, October 9-13,2005,707-708.
10Sui Zhen,Li Mingzhe,Liu Cbunguo,etc.Working surface design and control in multi-point forming of sheet metal, Proceedings of the 8th International Conference on Technology of Plasticity,Edizioni Progetto Padova, Verona, Italy, October 9-13,2005,581-582.
