http://reply.papertrans.cn/3/265/26419/26419-11.png
http://reply.papertrans.cn/3/265/26419/26419-12.png
http://reply.papertrans.cn/3/265/26419/26419-13.png
http://reply.papertrans.cn/3/265/26419/26419-14.png
Submitted on: 13 February 2006.
Revised on: 24 March 2006.
Accepted on: 14 April 2006.
Research in Mathematics Education
http://reply.papertrans.cn/3/265/26419/26419-16.png
Submitted on: 10 March 2003.
Revised on: 24 March 2003.
Accepted on: 31 March 2003.
Research in Mathematics Education
Submitted on: 22 January 2007.
Revised on: 09 February 2007.
Accepted on: 16 February 2007.
Research in Mathematics Education
Submitted on: 21 January 2012.
Revised on: 29 January 2012.
Accepted on: 12 February 2012.
NULL
Submitted on: 13 October 2010.
Revised on: 23 October 2010.
Accepted on: 04 November 2010.
Research in Mathematics Education