It's hard to hang out in a community of business owners and not hear someone mention this book by Chris Voss.
Voss led a successful career as a hostage negotiator for the FBI and transitioned to run a private consulting firm teaching negotiation skills.
There are some real gems in here around important topics such as:
Anchoring
Negotiation styles
Saying No without saying no
"Are you giving up on this project?"
Many of these techniques rhyme with the skills found in Sandler Sales, another classic skill set.
Voss uses a handful of case studies from his time in the FBI to convey these lessons.
Most of the stories have a "good outcome" thanks to these techniques.
The stories are engaging and worth the listen. Listen at 2x speed and learn the lessons again.
I came across this summary in github of all places. Have a look, and a listen.