Gaya APA

Collie, J., Slater, S. (2005). Speaking 4 : student's book/ Joanne Collie, Stephen Slater . Cambridge: Cambridge University Press.

Gaya MLA

Collie, Joanne., Slater, Stephen. "Speaking 4 : student's book/ Joanne Collie, Stephen Slater". Cambridge: Cambridge University Press, 2005. Text.