Cita APA (7th ed.)

Godin, S. (2002). Purple Cow: Transform your Questions (NA.). Penguin Books.

Cita Chicago (17th ed.)

Godin, Seth. Purple Cow: Transform Your Questions. NA. England: Penguin Books, 2002.

Cita MLA (9th ed.)

Godin, Seth. Purple Cow: Transform Your Questions. NA. Penguin Books, 2002.