Cita APA (7a ed.)

O'Connell, S. (1995). Focus on proficiency. T. Nelson.

Cita Chicago Style (17a ed.)

O'Connell, Sue. Focus on Proficiency. London: T. Nelson, 1995.

Cita MLA (8a ed.)

O'Connell, Sue. Focus on Proficiency. T. Nelson, 1995.