I just started reading a Dutch book about Design Thinking (as far as I know the only book in Dutch), "Design Thinking: Radicaal veranderen in kleine stappen" (in English: Radical change in small steps) by Guido Stompff. He starts with explaining different approaches to tackling a problem, which I found so interesting that I thought to share it here. It's only Chapter 1 of the book, so that sounds promising!