Cita APA (7th ed.)

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

Cita Chicago (17th ed.)

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

Cita MLA (8th ed.)

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