Cita APA (7th ed.)

ETHERTON, A. Contact 2: A secondary english course.-- rev. edition. Longman.

Cita Chicago (17th ed.)

ETHERTON, A.R.B. Contact 2: A Secondary English Course.-- Rev. Edition. London: Longman.

Cita MLA (9th ed.)

ETHERTON, A.R.B. Contact 2: A Secondary English Course.-- Rev. Edition. Longman.