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Submitted on: 15 April 2010.
Revised on: 25 June 2010.
Accepted on: 14 July 2010.
___________________International Journal of Economic Sciences
Submitted on: 23 December 2009.
Revised on: 13 February 2010.
Accepted on: 31 March 2010.
___________________International Journal of Economic Sciences
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Submitted on: 18 February 2003.
Revised on: 21 March 2003.
Accepted on: 10 May 2003.
___________________International Journal of Economic Sciences
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Submitted on: 19 July 2012.
Revised on: 10 September 2012.
Accepted on: 17 October 2012.
___________________International Journal of Economic Sciences