Cita APA (7a ed.)

Kerr, P., Jones, V., & Mauchline, F. (2007). Straightforward B2: Upper intermediate student's book. Macmillan.

Cita Chicago Style (17a ed.)

Kerr, Philip, Vaughan Jones, y Fiona Mauchline. Straightforward B2: Upper Intermediate Student's Book. Oxford: Macmillan, 2007.

Cita MLA (8a ed.)

Kerr, Philip, et al. Straightforward B2: Upper Intermediate Student's Book. Macmillan, 2007.