APA (7th ed.) Citation

Oxford University Press, Dunn, V., & Gruber, D. (1987). Listening intermediate: Oxford supplementary skills. Oxford University Press.

Chicago Style (17th ed.) Citation

Oxford University Press, V. Dunn, and D. Gruber. Listening Intermediate: Oxford Supplementary Skills. Oxford: Oxford University Press, 1987.

MLA (8th ed.) Citation

Oxford University Press, et al. Listening Intermediate: Oxford Supplementary Skills. Oxford University Press, 1987.