Cita APA (7a ed.)

Abbs, B., Freebairn, I., & Barker, C. (1978). In Focus 2: Student´s book-workbook. Longman.

Cita Chicago Style (17a ed.)

Abbs, Brian, Ingrid Freebairn, y Chris Barker. In Focus 2: Student´s Book-workbook. Exxes: Longman, 1978.

Cita MLA (9a ed.)

Abbs, Brian, et al. In Focus 2: Student´s Book-workbook. Longman, 1978.