APA (7e ed.) Bronvermelding

Crews, F. C. (1994). Speaking effectively: Developing speaking skills for business English. Cambridge University Press.

Chicago (17e ed.) Bronvermelding

Crews, Frederick C. Speaking Effectively: Developing Speaking Skills for Business English. Cambridge: Cambridge University Press, 1994.

MLA (8e ed.) Bronvermelding

Crews, Frederick C. Speaking Effectively: Developing Speaking Skills for Business English. Cambridge University Press, 1994.