"How to Read a Person Like a Book" by Gerard I. Nierenberg and Henry H. Calero is a classic guide to understanding body language and nonverbal communication. The book provides insights and techniques for interpreting facial expressions, posture, gestures, and other nonverbal cues to better understand people's thoughts, feelings, and intentions. With practical advice and real-life examples, the book helps readers improve their communication skills, build stronger relationships, and navigate social interactions more effectively.