Cita APA (7a ed.)

Alexander, L. (1974). New concept english: First things first : suplementary written exercises. Longman.

Cita Chicago Style (17a ed.)

Alexander, L.G. New Concept English: First Things First : Suplementary Written Exercises. London: Longman, 1974.

Cita MLA (9a ed.)

Alexander, L.G. New Concept English: First Things First : Suplementary Written Exercises. Longman, 1974.