Submitted on: 30 December 2002.
Revised on: 14 March 2003.
Accepted on: 04 April 2003.
___________________Environmental and Sustainability Indicators
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Submitted on: 30 August 2009.
Revised on: 03 October 2009.
Accepted on: 30 October 2009.
___________________Environmental and Sustainability Indicators
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Submitted on: 22 June 2006.
Revised on: 10 September 2006.
Accepted on: 31 October 2006.
___________________Environmental and Sustainability Indicators