APA (7th ed.) Citation

Gray, J., Farris, D., Warburton, B., & Cousins, G. (1992). Discovering english: A pre-intermediate course (2nd ed.). Mladex.

Chicago Style (17th ed.) Citation

Gray, Joanna, David Farris, Bob Warburton, and Gerry Cousins. Discovering English: A Pre-intermediate Course. 2nd ed. Bratislava: Mladex, 1992.

MLA (9th ed.) Citation

Gray, Joanna, et al. Discovering English: A Pre-intermediate Course. 2nd ed. Mladex, 1992.