Submitted on: 10 December 2000.
Revised on: 12 March 2001.
Accepted on: 07 April 2001.
___________________Applied Mathematics in Science and Engineering
Submitted on: 10 January 2001.
Revised on: 03 February 2001.
Accepted on: 02 April 2001.
___________________Applied Mathematics in Science and Engineering
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Submitted on: 26 August 1999.
Revised on: 08 December 1999.
Accepted on: 29 December 1999.
___________________Applied Mathematics in Science and Engineering
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Submitted on: 08 February 2008.
Revised on: 04 May 2008.
Accepted on: 03 June 2008.
___________________Applied Mathematics in Science and Engineering
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Submitted on: 19 January 2016.
Revised on: 06 March 2016.
Accepted on: 08 April 2016.
___________________Applied Mathematics in Science and Engineering