1. Sustainable Energy without the Hot Air, often abbreviated to SEWTHA, by David JC Mackay. It assesses how we use energy and assesses our options to provide it. A brilliant read, and the essential background to much of what follows. The aim of Sketchfifty is to produce ideas that add up from an energy perspective. Available free on the Internet. http://www.withouthotair.com/sewthacontents.shtml
2. The Entrepreneurial State by Mariana Mazzucato. Describes the limitations of the technology improvements that can be achieved by Private Enterprise. Private enterprise can only fund relatively low risk incremental technology development. Highly relevant to the development of new technologies of the type shown in Sketchfifty, because these are high risk and international government leadership will be essential if they are to be realised. Published by Anthem Press 2013
3. Walkable City –  Jeff Speck. Great book highlighting how to make cities that cater for walkers and cyclists, and the benefits of doing so. Published by FSG in 2012.
4. Fundamentals of Personal Rapid Transit Systems, Jack H Irving. This is a comprehensive Description of PRT systems. It dates from a time when Intellectual Property was less of a concern, and is therefore comprehensive and detailed. It gives considerable space to operate for newcomers in the PRT field since it defines a considerable amount of prior art. Published by Lexington Books, 1978. Out of print but available second hand.
5. The Age of Sustainable Development – Jeffrey Sachs. Takes a broad view of the issues to be addressed in achieving a sustainable life on this planet. Supremely sane. Very carefully and logically written. A must read.
6. The God Species – Mark Lynas. Well written and provocative. Condemns the well meaning efforts of some environmentalists. Makes a strong case that technology, including nuclear power and GM food, can and must play a part in a sustainable future.