Cita APA (7a ed.)

Kerr, P., & Jones, C. (2007). Straightforward: Upper intermediate Student's book (1st published.). MacMillan.

Cita Chicago Style (17a ed.)

Kerr, Philip, y Ceri Jones. Straightforward: Upper Intermediate Student's Book. 1st published. Oxford: MacMillan, 2007.

Cita MLA (9a ed.)

Kerr, Philip, y Ceri Jones. Straightforward: Upper Intermediate Student's Book. 1st published. MacMillan, 2007.