Cita APA (7a ed.)

O'Connor, J. D., Fletcher, C., & Kenworthy, J. (1990). Sounds English: : a pronunciation practice book. Longman.

Cita Chicago Style (17a ed.)

O'Connor, Joseph Desmond, Clare Fletcher, y Joanne Kenworthy. Sounds English: : A Pronunciation Practice Book. London [etc.]: Longman, 1990.

Cita MLA (9a ed.)

O'Connor, Joseph Desmond, et al. Sounds English: : A Pronunciation Practice Book. Longman, 1990.