APA (7th ed.) Citation

Singleton, D., & Lengyel, Z. (1995). The age factor in second language acquisition: A critical look at the critical period hypothesis. Muktilingual Matters LTD.

Chicago Style (17th ed.) Citation

Singleton, David, and Zsolt Lengyel. The Age Factor in Second Language Acquisition: A Critical Look at the Critical Period Hypothesis. Clevedon: Muktilingual Matters LTD, 1995.

MLA (9th ed.) Citation

Singleton, David, and Zsolt Lengyel. The Age Factor in Second Language Acquisition: A Critical Look at the Critical Period Hypothesis. Muktilingual Matters LTD, 1995.