Doff, A., Chiristopher Jones, & Keith Mitchell. (1983). Meanings into words: Intermediate : an integrated course for students of english : Student's book. New York: Cambridge University Press.

Doff, Adrian, Chiristopher Jones, và Keith Mitchell. Meanings Into Words: Intermediate : An Integrated Course for Students of English : Student's Book. New York: Cambridge University Press, 1983.

Doff, Adrian, Chiristopher Jones, và Keith Mitchell. Meanings Into Words: Intermediate : An Integrated Course for Students of English : Student's Book. New York: Cambridge University Press, 1983.