The list is not exhaustive and is being constantly updated:
Byrgrave, L 2014 Data Privacy Law: An International Perspective
Carey, P 2009 Data Protection: A Practical Guide to UK and EU Law
Gutwirth, S et al. 2011 Computers, privacy and data protection: an element of choice
Gutwirth, S et al. 2013 European data protection: coming of age
Gutwirth, S et al. 2012 European Data Protection: In Good Health?
Kulesza, J 2012 International Internet Law
Kuner, C 2013 Transborder Data Flows and Data Privacy Law (Hardback)
Sotto, L 2013 Privacy and data security law deskbook
Wright, D 2012 Privacy Impact Assessment
More books on data protection available here