Cita APA (7a ed.)

Abercrombie, D. (1957). Problems and Principles: Studies in the Teaching of English as a Second Language. Longmans.

Cita Chicago Style (17a ed.)

Abercrombie, David. Problems and Principles: Studies in the Teaching of English as a Second Language. London: Longmans, 1957.

Cita MLA (9a ed.)

Abercrombie, David. Problems and Principles: Studies in the Teaching of English as a Second Language. Longmans, 1957.