This comprehensive guide is a good introduction to pop-up and folding paper sculpture engineering. Aimed at all levels of ability.
Duncan Birmingham has taught paper mechanics at university level for 20 years and has an extensive library of books on pop-up. He is the author of several books on the subject and his Pop-Up! A Manual of Paper Mechanisms 9781899618095 was hailed the most comprehensive book, to date, on the subject. He lives in Bristol. Also available: Making Mechanical Cards 9781861086358