Cita APA (7a ed.)
Abbs, B., & Freebairn, I. (1990). Opening Strategies. Strategies 1. An Integrated Language Course for Beginners of English. Students' Book (23rd impression.). Longman Group UK.
Cita Chicago Style (17a ed.)
Abbs, Brian, y Ingrid Freebairn. Opening Strategies. Strategies 1. An Integrated Language Course for Beginners of English. Students' Book. 23rd impression. Harlow: Longman Group UK, 1990.
Cita MLA (9a ed.)
Abbs, Brian, y Ingrid Freebairn. Opening Strategies. Strategies 1. An Integrated Language Course for Beginners of English. Students' Book. 23rd impression. Longman Group UK, 1990.
Precaución: Estas citas no son 100% exactas.