Spencer Johnson - Who moved my cheese?

I really like this book because it helps you to think differently and not to stay constantly in your lane. Be proactive and try new things.

Simon Sinek - Start with why

This book helps you a lot with storytelling. How do you frame your story so that it reaches your audience?

Martin L. Puterman - Markov Decision Processes: discrete stochastic dynamic programming

This is the book from which I learned much about mathematical theory for mathematical decision-making. It has shaped my career and is material that I use daily in my work.