Gaya APA

Chaffey, D., Chadwick, F, E. (2016). Digital marketing : strategy, implementation and practice (6th ed.). : Pearson Education.

Gaya MLA

Chaffey, Dave., Chadwick, Fiona, Elis. "Digital marketing : strategy, implementation and practice". 6th ed. : Pearson Education, 2016. Buku/Printed Material.