APA-referens (7:e uppl.)

Harden, L., & Heyman, B. (2009). Digital engagement: Internet marketing that captures customers and builds intense brand loyalty. American Management Association.

Chicago-referens (17:e uppl.)

Harden, Leland, och Bob Heyman. Digital Engagement: Internet Marketing That Captures Customers and Builds Intense Brand Loyalty. New York: American Management Association, 2009.

MLA-referens (9:e uppl.)

Harden, Leland, och Bob Heyman. Digital Engagement: Internet Marketing That Captures Customers and Builds Intense Brand Loyalty. American Management Association, 2009.