Lower Secondary School Students' Understanding of Algebraic Proof. Proceedings of 33rd Conference of International Group for PME(Psychology of Mathematics Education). 2009. 3. 441-448
”Why do we have to prove this?” Fostering Students' Understanding of 'Proof' in Geometry in Lower Secondary School. Proceedings of ICMI Study 19 on ”Proof and Proving in Mathematics Education”. 2009. 1. 256-261
Lower Secondary School Students' Understanding of Algebraic Proof. Proceedings of 33rd Conference of International Group for PME(Psychology of Mathematics Education). 2009. 3. 441-448
”Why do we have to prove this?” Fostering Students' Understanding of 'Proof' in Geometry in Lower Secondary School. Proceedings of ICMI Study 19 on ”Proof and Proving in Mathematics Education”. 2009. 1. 256-261