Since this book was first published in 2009 a great number of people have contributed time and information. Everything from writing book chapters through to the editing the book. In alphabetical order these are:

• Wendy Bedgegood
• Dr Trevor Bretag
• Dr Vicki Elliot
• Dr Angela Freeman
• Frank Henry
• Dr Pragya Kant
• Helen Richardson
• Dr Matthew Rodda
• Dr Merrin Spackmann
• Dr Jason Brand
• Sarah Brown

We would particularly like to thank our external reviewers, Dr Kurt Lindbeck and Dr Fran Lopez-Ruiz, for contributions to the 2018 and 2022 editions.