ISSUES OF SUSTAINABILITYRisk & The Precautionary Principle Introduction Revised 31 August 2021 ***** Sources of content (sources to be added) Sprent, P. Taking Risks: The Science of Uncertainty. London, Penguin Books, 1988. Taleb, N.N. The Black Swan: The Impact of the Highly Improbable. New York, Random House, 2007.