Las cuatro tendencias: Los perfiles básicos de personalidad que te enseñan a mejorar tu vida (y la de los demás) (The Indispensable Personality Profiles That Reveal How to Make Your Life Better (and Other People's Lives Better, Too)Gretchen Rubin
The Happiness Project: Or, Why I Spent a Year Trying to Sing in the Morning, Clean My Closets, Fight Right, Read Aristotle, and Generally Have More FunGretchen Rubin4.1