APA (7th ed.) Citation

Gordon, K., Robards, J., & Williams, M. (1978). Core book. Macdonald.

Chicago Style (17th ed.) Citation

Gordon, Keith, John Robards, and Michael Williams. Core Book. London: Macdonald, 1978.

MLA (9th ed.) Citation

Gordon, Keith, et al. Core Book. Macdonald, 1978.