1. ANZ (Standards Australia/Standards New Zealand). 1995. Risk Management AS/NZS 430:1995 Homebush, NSW, Australia and Wellington, New Zealand
2. Economic Analysis of Environmental Policy and Regulation;Arnold,1995
3. Detecting influential observations in linear regression;Cook;Technometrics,1977
4. Council on Environmental Quality. 1991. Environmental Quality: 21st Annual Report 1990. U.S. Government Printing Office, Washington, D.C
5. Applied Regression Analysis;Draper,1981