1. Z.Y. WU, H.G. QIAO, W.P. HU. A: Journal of Shenyang University of Technology, Vol. 30, No. 2(2008), pp.228-232.
2. Y.X. LUO, J.R., ZHOU: Journal of Mechanical Strength, Vol. 18, No, 3(1996), pp.60-63.
3. Y.X. LUO, X. WU, M. LI: Journal of Mechanical Strength, Vol. 24, No. 3(2002), pp.450-452.
4. W. Z. DAI, J. F. LI : Systems Engineering—Theory & Practice, Vol. 25, No. 9(2005), pp.89-93.
5. B.H. YANG Z.Q. ZHANG : Mathematics in Practice and Theory, Vol. 33, No. 10(2003), pp.21-25.