@book{12057,
	author = {Harley, Birgit. and Ontario Institute for Studies in Education.},
	title = {The Development of second language proficiency /},
	publisher = {Cambridge University Press,},
	year = {1990 [printing 1996].},
	series = {The Cambridge applied linguistics series},
	address = {Cambridge ;},
	note = {Papers prepared for a symposium held at the Ontario Institute for Studies in Education, November 1987.}
}