Buchanan, William J, Imran, Muhammad Ali, Ur-Rehman, Masood, Zhang, Lei, Abbasi, Qammer H, Chrysoulas, Christos, Haynes, David, Pitropakis, Nikolaos, Papadopoulos, Pavlos, "Review and Critical Analysis of Privacy-preserving Infection Tracking and Contact Tracing", Frontiers in Communications and Networks, 2020