APA-viite (7. p.)
DiJulius, J. R. (2003). Secret service: Hidden systems that deliver unforgettable customer service. AMACOM.
Chicago-viite (17. p.)
DiJulius, John R. Secret Service: Hidden Systems That Deliver Unforgettable Customer Service. New York: AMACOM, 2003.
MLA-viite (9. p.)
DiJulius, John R. Secret Service: Hidden Systems That Deliver Unforgettable Customer Service. AMACOM, 2003.
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