Charan, R. (2008). What the Customer Wants You to Know. Penguin Group.
Chicago Style aipamenaCharan, Ram. What the Customer Wants You to Know. New Delhi: Penguin Group, 2008.
MLA aipamenaCharan, Ram. What the Customer Wants You to Know. Penguin Group, 2008.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.