Lua APA (7ú heag.)

Ginsburg, H., & Opper, S. (1998). Pïaget's theory of intellectual development. UNESCO.

Lua i Stíl Chicago (17ú heag.)

Ginsburg, Herbert, agus Sylvia Opper. Pïaget's Theory of Intellectual Development. París, Francia: UNESCO, 1998.

Lua MLA (9ú heag.)

Ginsburg, Herbert, agus Sylvia Opper. Pïaget's Theory of Intellectual Development. UNESCO, 1998.

Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.