Cita APA (7th ed.)

Gatenby, E. V. (1972). A direct method english course. Longman.

Cita Chicago (17th ed.)

Gatenby, E. V. A Direct Method English Course. London: Longman, 1972.

Cita MLA (9th ed.)

Gatenby, E. V. A Direct Method English Course. Longman, 1972.