APA (7th ed.) Zitazioa

Etherton, A. (1968). Objective english tests intermediate level. Longman.

Chicago Style (17th ed.) Zitazioa

Etherton, A.R.B. Objective English Tests Intermediate Level. London: Longman, 1968.

MLA (9th ed.) Zitazioa

Etherton, A.R.B. Objective English Tests Intermediate Level. Longman, 1968.