Citazione Stile APA (7a Edizione)

DiJulius, J. R. (2003). Secret service: Hidden systems that deliver unforgettable customer service. AMACOM.

Citazione stile Chigago Style (17a edizione)

DiJulius, John R. Secret Service: Hidden Systems That Deliver Unforgettable Customer Service. New York: AMACOM, 2003.

Citatione MLA (9a ed.)

DiJulius, John R. Secret Service: Hidden Systems That Deliver Unforgettable Customer Service. AMACOM, 2003.