1. BOSCHETTO P. Res Med, Vol. 95(2001), pp.357-362.
2. LITTORIN M and RYLANDER L. Occup Environ Med, Vol. 57 (2000), pp.396-405.
3. H. W. Zhang and Y. J. Xu Foreign Medical: Health Science volumes, Vol. 29(2002), pp.204-205.
4. MARCZYNSKI B. Toxic Ind. Health, Vol. 8(1992), pp.157-169.
5. Y. B. Ji, L. Lang and H. Jiang. Journal of Toxicology, Vol. 20(2006), pp.38-39.