@book{18102,
	author = {Kieran, Carolyn||Pang, JeongSuk||Schifter, Deborah||Ng, Swee Fong},
	title = {Early Algebra: Research into its Nature, its Learning, its Teaching},
	url = {https://library.oapen.org/bitstream/20.500.12657/27822/1/1002183.pdf||https://library.oapen.org/bitstream/20.500.12657/27822/1/1002183.pdf||https://library.oapen.org/bitstream/20.500.12657/27822/1/1002183.pdf}
}