Cita APA (7a ed.)

Abbs, B., & Freebairn, I. (1985). Opening Strategies. Students' book. Strategies 1. Longman.

Cita Chicago Style (17a ed.)

Abbs, Brian, y Ingrid Freebairn. Opening Strategies. Students' Book. Strategies 1. Essex: Longman, 1985.

Cita MLA (9a ed.)

Abbs, Brian, y Ingrid Freebairn. Opening Strategies. Students' Book. Strategies 1. Longman, 1985.