Submitted on: 19 November 2015.
Revised on: 12 February 2016.
Accepted on: 05 March 2016.
___________________Informatics in Education---VILNIUS UNIV, INST MATHEMATICS & INFORMATICS
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Submitted on: 11 October 2006.
Revised on: 02 February 2007.
Accepted on: 30 March 2007.
___________________Informatics in Education---VILNIUS UNIV, INST MATHEMATICS & INFORMATICS
Submitted on: 20 November 2015.
Revised on: 14 December 2015.
Accepted on: 06 January 2016.
___________________Informatics in Education---VILNIUS UNIV, INST MATHEMATICS & INFORMATICS
Submitted on: 09 March 2017.
Revised on: 26 April 2017.
Accepted on: 07 May 2017.
___________________Informatics in Education---VILNIUS UNIV, INST MATHEMATICS & INFORMATICS
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Submitted on: 12 April 2000.
Revised on: 09 August 2000.
Accepted on: 23 September 2000.
___________________Informatics in Education---VILNIUS UNIV, INST MATHEMATICS & INFORMATICS