Cita APA (7th ed.)

ETHERTON, A. (1977). Contact 3: A secondary english course.-- Ed.Revised. Longman.

Cita Chicago (17th ed.)

ETHERTON, A.R.B. Contact 3: A Secondary English Course.-- Ed.Revised. Kuala Lumpur: Longman, 1977.

Cita MLA (9th ed.)

ETHERTON, A.R.B. Contact 3: A Secondary English Course.-- Ed.Revised. Longman, 1977.