Cita APA (7th ed.)

Corder, S. (1971). An intermediate english practice book: Key to the exercises. Longman.

Cita Chicago (17th ed.)

Corder, S.Pit. An Intermediate English Practice Book: Key to the Exercises. London: Longman, 1971.

Cita MLA (9th ed.)

Corder, S.Pit. An Intermediate English Practice Book: Key to the Exercises. Longman, 1971.