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Submitted on: 05 June 2011.
Revised on: 21 August 2011.
Accepted on: 10 October 2011.
___________________Geography and Sustainability---ELSEVIER
Submitted on: 06 October 2008.
Revised on: 16 January 2009.
Accepted on: 09 March 2009.
___________________Geography and Sustainability---ELSEVIER
Submitted on: 23 December 2016.
Revised on: 31 March 2017.
Accepted on: 12 April 2017.
___________________Geography and Sustainability---ELSEVIER
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