APA (7e ed.) Bronvermelding

Hayes, B. E. (2009). Beyond the ultimate question: A systematic approach to improve customer loyalty. ASQ Quality Press.

Chicago (17e ed.) Bronvermelding

Hayes, Bob E. Beyond the Ultimate Question: A Systematic Approach to Improve Customer Loyalty. Milwaukee, Wisconsin: ASQ Quality Press, 2009.

MLA (9e ed.) Bronvermelding

Hayes, Bob E. Beyond the Ultimate Question: A Systematic Approach to Improve Customer Loyalty. ASQ Quality Press, 2009.