Submitted on: 04 August 2015.
Revised on: 27 August 2015.
Accepted on: 12 September 2015.
Perspectiva Educacional---EDICIONES UNIV VALPARAISO
http://reply.papertrans.cn/3/244/24303/24303-22.png
Submitted on: 26 September 2009.
Revised on: 15 October 2009.
Accepted on: 10 November 2009.
NULL
Submitted on: 14 November 2001.
Revised on: 27 November 2001.
Accepted on: 14 December 2001.
Perspectiva Educacional---EDICIONES UNIV VALPARAISO
Submitted on: 12 October 2022.
Revised on: 27 October 2022.
Accepted on: 21 November 2022.
NULL
Submitted on: 17 January 2002.
Revised on: 21 February 2002.
Accepted on: 27 February 2002.
NULL
http://reply.papertrans.cn/3/244/24303/24303-27.png
Submitted on: 01 June 2008.
Revised on: 27 June 2008.
Accepted on: 10 July 2008.
NULL
http://reply.papertrans.cn/3/244/24303/24303-29.png
Submitted on: 06 December 2001.
Revised on: 10 January 2002.
Accepted on: 30 January 2002.
Perspectiva Educacional---EDICIONES UNIV VALPARAISO