Cita APA (7a ed.)

Abbs, B., & Ayton, A. (1977). Strategies. Students' Book. Longman.

Cita Chicago Style (17a ed.)

Abbs, Brian, y Angela Ayton. Strategies. Students' Book. Londres: Longman, 1977.

Cita MLA (9a ed.)

Abbs, Brian, y Angela Ayton. Strategies. Students' Book. Longman, 1977.