Cita APA (7th ed.)

Cobb, D. (1978). Puzzles for english practice: PEP 2. Longman.

Cita Chicago (17th ed.)

Cobb, David. Puzzles for English Practice: PEP 2. Londres: Longman, 1978.

Cita MLA (9th ed.)

Cobb, David. Puzzles for English Practice: PEP 2. Longman, 1978.