The Bielefeld interdisciplinary project & Immelmann, K. (1981). Behavioral development: The Bielefeld Interdisciplinary project. Cambridge University Press.
Lua i Stíl Chicago (17ú heag.)The Bielefeld interdisciplinary project agus Klaus Immelmann. Behavioral Development: The Bielefeld Interdisciplinary Project. New York: Cambridge University Press, 1981.
Lua MLA (9ú heag.)The Bielefeld interdisciplinary project agus Klaus Immelmann. Behavioral Development: The Bielefeld Interdisciplinary Project. Cambridge University Press, 1981.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.