Hi thecattery Glad to have you aboard! Quite an undertaking you have there. I take my hat off to you. I couldn't do it. I have a friend who is the head of RE, she should know. I'll post a message ASAP. The traditional books are often better than some of the knew ones. The actual subject matter has not really changed. For my money for maths invest in some Bostock and Chandler books they are the best around. I get all my examples from them. Any other queries just post.