Cita APA (7a ed.)

Oï Dell, F., & Broadhead, A. (2008). Objective advanced: Student's book with answers (2a. ed.). Cambridge University Press.

Cita Chicago Style (17a ed.)

Oï Dell, Felicity, y Annie Broadhead. Objective Advanced: Student's Book with Answers. 2a. ed. Cambridge: Cambridge University Press, 2008.

Cita MLA (9a ed.)

Oï Dell, Felicity, y Annie Broadhead. Objective Advanced: Student's Book with Answers. 2a. ed. Cambridge University Press, 2008.