https://norman.hrc.utexas.edu/Watch/fob_search_results_next....
Here's another thing you can do... search LinkedIn for people who previously worked at Harper Collins, and cold email a few of them and say "Hey, I see you used to work at HC, I'm trying to work on a deal with them, could I pick your brain for a few minutes". Quite a few people will likely happily agree to a brief phone call / video chat, to help you out. Talk to a couple of such people and there's a good chance one of them will be able to point you in the right direction, and maybe even give you a warm introduction to the person you need to talk to.
He also ran a successful kickstarter this year to deliver a hard bound anthology of the presidiums digital only works. I bought one because I’ve been freeloading by reading the free versions on his website. I suspect many of the other Kickstarter backers were in a similar situation. Thanks Joe!