APA Citation

Harley, B. (1990). The Development of second language proficiency. Cambridge University Press.

Chicago Style Citation

Harley, Birgit. The Development of Second Language Proficiency. Cambridge University Press, 1990.

MLA Citation

Harley, Birgit. The Development of Second Language Proficiency. Cambridge University Press, 1990.

Warning: These citations may not always be 100% accurate.