توثيق جمعية علم النفس الأمريكية APA (الطبعة السابعة)

Piper, T. (2001). And then there were two: Children and second language learning. Pippin Pub..

توثيق أسلوب شيكاغو (الطبعة السابعة عشر)

Piper, Terry. And Then There Were Two: Children and Second Language Learning. Toronto: Pippin Pub., 2001.

توثيق جمعية اللغة المعاصرة MLA (الإصدار التاسع)

Piper, Terry. And Then There Were Two: Children and Second Language Learning. Pippin Pub., 2001.