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http://reply.papertrans.cn/3/265/26418/26418-22.png
Submitted on: 28 June 2001.
Revised on: 27 July 2001.
Accepted on: 20 August 2001.
Research in Mathematics---TAYLOR & FRANCIS LTD
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Submitted on: 22 December 2005.
Revised on: 08 January 2006.
Accepted on: 17 January 2006.
Research in Mathematics---TAYLOR & FRANCIS LTD
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Submitted on: 16 December 2002.
Revised on: 23 January 2003.
Accepted on: 15 February 2003.
Research in Mathematics
Submitted on: 19 March 2001.
Revised on: 16 April 2001.
Accepted on: 25 April 2001.
Research in Mathematics---TAYLOR & FRANCIS LTD
Submitted on: 11 November 2020.
Revised on: 27 November 2020.
Accepted on: 14 December 2020.
Research in Mathematics
Submitted on: 06 June 2013.
Revised on: 03 July 2013.
Accepted on: 14 July 2013.
Research in Mathematics