Dennis Kleine https://www.linkedin.com/in/denniskleine/

Growth Hacking https://www.amazon.com/Hacking-Growth-Fastest-Growing-Companies-Breakout/dp/045149721X

Lean Startup & Lean UX https://www.amazon.de/Lean-Startup-Entrepreneurs-Continuous-Innovation/dp/0307887898 https://www.amazon.de/Lean-UX-Designing-Great-Products/dp/1491953608