Paper  bibtex   

@article{grazzini_montessori_2004,
	title = {The {Montessori} {Approach} to {Mathematics}},
	volume = {29},
	url = {http://www.worldcat.org/oclc/11228546},
	language = {eng},
	number = {1},
	journal = {NAMTA Journal},
	author = {Grazzini, Camillo},
	year = {2004},
	pages = {69--78}
}