@conference {19833,
	title = {Reifying algebraic-like equations in the context of constructing and controlling animated models},
	booktitle = {Proceedings of the 33rd Conference of the International Group for the Psychology of Mathematics Education (PME 33)},
	volume = {4},
	year = {2009},
	pages = {425-432},
	publisher = {PME},
	organization = {PME},
	address = {Thessaloniki, Greece},
	author = {G Psycharis and F Moustaki and C Kynigos},
	editor = {M. Tzekaki and M Kaldrimidou and C Sakonidis}
}
