I regret I'm unable to answer multiple questions from individuals, due to the number of requests that arrive daily.
I'm also no longer able to offer online talks or chat sessions.
Please check your email address before sending. My replies to one in five of the messages I receive bounce back
because the address is not recognised, or a school firewall is preventing my reply getting through.
If you don't get a response within a day or so, that willl be the reason.