Cita APA (7a ed.)

Lloyd, M., & Day, J. (2011). Active grammar: Level 3 : with answers. Cambridge University Press.

Cita Chicago Style (17a ed.)

Lloyd, Mark, y Jeremy Day. Active Grammar: Level 3 : With Answers. Cambridge: Cambridge University Press, 2011.

Cita MLA (9a ed.)

Lloyd, Mark, y Jeremy Day. Active Grammar: Level 3 : With Answers. Cambridge University Press, 2011.