APA-referens (7:e uppl.)

Soars, L., & Soars, L. (2010). American Headway 4: The world's most trusted English course (2a. ed.). Oxford University Press.

Chicago-referens (17:e uppl.)

Soars, Liz, och Liz Soars. American Headway 4: The World's Most Trusted English Course. 2a. ed. Nueva York: Oxford University Press, 2010.

MLA-referens (9:e uppl.)

Soars, Liz, och Liz Soars. American Headway 4: The World's Most Trusted English Course. 2a. ed. Oxford University Press, 2010.