APA (7th ed.) Zitazioa

Langan, J. (1981). English Skills (2nd ed.). McGraw-Hill.

Chicago Style (17th ed.) Zitazioa

Langan, John. English Skills. 2nd ed. New York: McGraw-Hill, 1981.

MLA (9th ed.) Zitazioa

Langan, John. English Skills. 2nd ed. McGraw-Hill, 1981.