APA ציטוט

O'Brien, D. (2008). Penguin yearbook 2009. Penguin Books.

Chicago Edition Citation

O'Brien, Derek. Penguin Yearbook 2009. New Delhi: Penguin Books, 2008.

ציטוט MLA

O'Brien, Derek. Penguin Yearbook 2009. Penguin Books, 2008.