APA (7th ed.) Citation

Singleton, D. M., & Ryan, L. (2004). Language acquisition: The age factor (2nd ed.). Multilingual Matters.

Chicago Style (17th ed.) Citation

Singleton, D. M., and Lisa Ryan. Language Acquisition: The Age Factor. 2nd ed. Clevedon ; Buffalo: Multilingual Matters, 2004.

MLA (9th ed.) Citation

Singleton, D. M., and Lisa Ryan. Language Acquisition: The Age Factor. 2nd ed. Multilingual Matters, 2004.