On the topic of negotiations, I would recommend a book “Never Split the difference” by Chris Voss a former FBI hostage negotiator.
He takes you through his own experience of handling various hostage situations, salary negotiations etc.
This book has created a whole class of very annoying people who do nothing but repeat "How can you make this deal better for me at no cost to myself" in an endless loop and have no strategy for what to do when the other party isn't willing to negotiate themselves downwards for free.
I read all the classic negotiations books and think this one is the only one you need to read. IMO its core idea is NOT "how am I supposed to do that", as other posters say, but the role of empathy and uncovering hidden information in high-stakes (or even regular) negotiations
