Credit: World Scientific The book is state-of-the-art and state-of-the-practice summary of structural and geotechnical engineering from theory to practice since 1950's and Wai-Fah Chen's tribute to his role models, Daniel C. Drucker, Lynn S. Beedle and more. When the mathematical theory of plasticity was first introduced to civil engineers in the 1950s under the leadership of William Prager of Brown University, the topic was taught in the applied mathematics department with tensor notations that were hardly readable and understandable for most civil engineers. In this period, the classical incremental plasticity theory was in its golden time, but our computing capability in engineering practice was in its infancy. We had a rigorous theory but few practical solutions.