Cita APA (7a ed.)

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

Cita Chicago Style (17a ed.)

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

Cita MLA (9a ed.)

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