APA (7th ed.) Citation

Parry, A., Bartram, M., & Hartle, S. (1989). Penguin elementary writing skills. Penguin Books.

Chicago Style (17th ed.) Citation

Parry, Anne, Mark Bartram, and Sharon Hartle. Penguin Elementary Writing Skills. London: Penguin Books, 1989.

MLA (9th ed.) Citation

Parry, Anne, et al. Penguin Elementary Writing Skills. Penguin Books, 1989.