Submitted on: 30 October 2005.
Revised on: 15 November 2005.
Accepted on: 06 December 2005.
QME-Quantitative Marketing and Economics
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Submitted on: 22 October 2005.
Revised on: 05 November 2005.
Accepted on: 23 November 2005.
QME-Quantitative Marketing and Economics
Submitted on: 26 February 2010.
Revised on: 10 March 2010.
Accepted on: 21 March 2010.
QME-Quantitative Marketing and Economics
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