Cita APA (7th ed.)

Allen, W. S. (1974). Living english structure: Key to the exercises. Longman.

Cita Chicago (17th ed.)

Allen, W. Stannard. Living English Structure: Key to the Exercises. Londres: Longman, 1974.

Cita MLA (9th ed.)

Allen, W. Stannard. Living English Structure: Key to the Exercises. Longman, 1974.