Cita APA (7a ed.)

Adamson, D., & Cobb, D. (1987). Active grammar exercises. Longman.

Cita Chicago Style (17a ed.)

Adamson, D., y D. Cobb. Active Grammar Exercises. Essex: Longman, 1987.

Cita MLA (8a ed.)

Adamson, D., y D. Cobb. Active Grammar Exercises. Longman, 1987.