Cita APA (7a ed.)
O'Connell, S. (1992). Focus on Advanced English. C.A.E. Addison Wesley Longman Ltd.
Cita Chicago Style (17a ed.)
O'Connell, Sue. Focus on Advanced English. C.A.E. Harlow: Addison Wesley Longman Ltd, 1992.
Cita MLA (9a ed.)
O'Connell, Sue. Focus on Advanced English. C.A.E. Addison Wesley Longman Ltd, 1992.
Precaución: Estas citas no son 100% exactas.