Citazione Stile APA (7a Edizione)

LUBIS, Y. (1988). Developing communicative proficiency in the english asa foreign language (EFL) class. Depdikbud.

Citazione stile Chigago Style (17a edizione)

LUBIS, Yusnaini. Developing Communicative Proficiency in the English Asa Foreign Language (EFL) Class. Jakarta: Depdikbud, 1988.

Citatione MLA (9a ed.)

LUBIS, Yusnaini. Developing Communicative Proficiency in the English Asa Foreign Language (EFL) Class. Depdikbud, 1988.