APA
Parkin G., . (2009). Digital marketing. London: New Holland Publishers (UK) ltd.
Chicago
Parkin Godfrey, . 2009. Digital marketing. London: New Holland Publishers (UK) ltd.
Harvard
Parkin G., . (2009). Digital marketing. London: New Holland Publishers (UK) ltd.
MLA
Parkin Godfrey, . Digital marketing. London: New Holland Publishers (UK) ltd. 2009.