4Robert Goodland, Herman Daly. Environmental Sustainability: Universal and Non-Negoatiable Ecological Applications, Ecological society of America, 1996,6 ( 4 ) : 1002 -1017.
5Biswajit Dhar. Trade and Environment:the GATT Perspective. Economic and Political weekly, 1992,27 ( 22 ) : 1123-1124.
6John, S. Wilson, Mirvat Sewadeh, Tsunehiro Otsuki. Dirty Exports and Environmental Regulation : Do standards matter? Development Research Group (GDCRG) ,The World Bank ,2001.