Arrange the following reference in APA format
Chaffey, D., & Ellis-Chadwick, F. (2019). Digital Marketing: Strategy, Implementation, and Practice. Pearson Education Limited.
2. Ryan, D., & Jones, C. (2009). Understanding digital marketing: marketing strategies for engaging the digital generation. Kogan Page Publishers.
3. Smith, P. R., & Zook, Z. (2011). Marketing communications: integrating offline and online with social media. Kogan Page Publishers.
Chaffey, D., & Ellis-Chadwick, F. (2019). Digital Marketing: Strategy, Implementation, and Practice. Pearson Education Limited.
Ryan, D., & Jones, C. (2009). Understanding digital marketing: marketing strategies for engaging the digital generation. Kogan Page Publishers.
Smith, P. R., & Zook, Z. (2011). Marketing communications: integrating offline and online with social media. Kogan Page Publishers.