There are many books on etiquette, interpersonal relationships, and how to deal with people. The following are a few popular recommendations: 1. The Social Animal: Author Richard Griggs explains the principles and techniques of social psychology through studying animal social behavior, which is very helpful in improving interpersonal skills. 2. The Art of War: Sun Tzu explained the basic principles and skills of interpersonal relationships through the description of war strategies, which was also very helpful in improving interpersonal skills. The Good Sheep and the King: The author, John Locke, tells the story of a sheep and a king. Through this story, he explains the basic principles and skills of interpersonal communication, which are very helpful in improving interpersonal skills. How to Talk So People Will Listen & Listen So People Will Talk: Author Carlos Castanida introduced some effective communication skills, including listening, expressing one's views, and avoiding conflicts, which are very helpful in improving interpersonal skills. 5 Nonviolent Communication: Author Martin Seligman introduced an effective communication technique called nonviolent communication. Through this method, people can better understand themselves and others and improve their interpersonal skills. These books are classic works on interpersonal relationships and how to deal with people. They can help you better understand these topics and improve your interpersonal skills.