Crain, W. C. (1992). Theories of developemnt: Concepts and applications (3rd ed.). Prentice-Hall.
Lua i Stíl Chicago (17ú heag.)Crain, William C. Theories of Developemnt: Concepts and Applications. 3rd ed. Englewood Cliffs, New Jersey: Prentice-Hall, 1992.
Lua MLA (9ú heag.)Crain, William C. Theories of Developemnt: Concepts and Applications. 3rd ed. Prentice-Hall, 1992.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.