Submitted on: 24 November 2016.
Revised on: 04 January 2017.
Accepted on: 22 January 2017.
Romanian Statistical Review---NATL INST STATISTICS
Submitted on: 13 March 2019.
Revised on: 15 April 2019.
Accepted on: 13 May 2019.
Romanian Statistical Review---NATL INST STATISTICS
Submitted on: 05 November 2012.
Revised on: 06 December 2012.
Accepted on: 15 December 2012.
Romanian Statistical Review
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Submitted on: 03 September 2011.
Revised on: 11 September 2011.
Accepted on: 06 October 2011.
Romanian Statistical Review
Submitted on: 04 December 2005.
Revised on: 22 December 2005.
Accepted on: 08 January 2006.
Romanian Statistical Review---NATL INST STATISTICS
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