1. R.A. Thompon: Trans. ASME, (1971), p.492.
2. X. S. He, W Peng and Z. Y. Weng: Proc. of the 11th Conf. on Production Research, (1991), p.927.
3. J. Verkerk: Annals of the CIRP Vol. 26 (1997) No. 2, p.385.
4. Z.Y. Weng, W.D. Xie, B. Lu, Y.W. Ye, H. Yao and X.S. He: Key Engineering Materials, Vol. 259-2 (2004), pp.352-356.