Cita APA (7a ed.)

Hewings, M. (2009). Grammar for CAE and proficiency with answers: Self-study grammar reference and practice. Cambridge University Press.

Cita Chicago Style (17a ed.)

Hewings, Martin. Grammar for CAE and Proficiency with Answers: Self-study Grammar Reference and Practice. Cambridge: Cambridge University Press, 2009.

Cita MLA (9a ed.)

Hewings, Martin. Grammar for CAE and Proficiency with Answers: Self-study Grammar Reference and Practice. Cambridge University Press, 2009.