Chaffey, D., & Smith, P. R. (2017). Digital Marketing Excellence: Planning, Optimizing and Integrating Online Marketing (5th ed.). Routledge An Imprint of Taylor & Francis Group.

Chaffey, Dave, and P. R. Smith. Digital Marketing Excellence: Planning, Optimizing and Integrating Online Marketing. 5th ed. New York: Routledge An Imprint of Taylor & Francis Group, 2017.

Chaffey, Dave, and P. R. Smith. Digital Marketing Excellence: Planning, Optimizing and Integrating Online Marketing. 5th ed. Routledge An Imprint of Taylor & Francis Group, 2017.