제목: Walden Two 저자: B. F. Skinner Hackett Publishing Company, Inc.; 1 edition (July 15, 2005) https://www.amazon.com/Walden-Two-Hackett-Classics-Skinner/dp/0872207781/ref=sr_1_1?s=books&ie=UTF8&qid=1535524566&sr=1-1&keywords=Walden+two
