Dan Harris’s Substack 'Self-help for smart people' is included because it provides practical self-help techniques and decision-making frameworks that directly support the book’s PART 3: Capital in Action and the chapter 'Your Capital In Action' (page 138), offering actionable strategies to improve self-regulation, reduce cognitive bias, and sharpen investment judgment; I confirmed the newsletter’s focus on pragmatic self-help on the author’s site and linked those insights to the book’s emphasis on applying personal capital effectively to make smarter investment decisions.