Willpower: 21 Day Challenge to Push Through Anything, Resist Temptation and Achieve Your Goals - How to Keep Going When You Want to Give Up Paperback – Import, 27 February 2019

The writing style reminds me greatly of The Power of Habit in that the vast majority of the book is anecdotal and case study summation. In fact, I could quite easily get literally 100% of the book's usefulness in a 30 minute Ted Talk if done correctly.