*Block, J. (2016). Flexible algebraic action on quadratic equations. In: Krainer, K. & N. Vondrová (Hrsg.), Proceedings of the [[Ninth Conference of European Research in Mathematics Education]] (CERME9). Prag: Charles University in Prague, Faculty of Education and [[ERME]]. 391-397. | *Block, J. (2016). Flexible algebraic action on quadratic equations. In: Krainer, K. & N. Vondrová (Hrsg.), Proceedings of the [[Ninth Conference of European Research in Mathematics Education]] (CERME9). Prag: Charles University in Prague, Faculty of Education and [[ERME]]. 391-397. |