Research on Kelsen's theory and practice in the history of rule of law 并列题名:Research on Kelsen's theory and practice in the history of rule of law Research on the theory and practice of real estate law Research on the theory and practice of e-business based on C2C Research on the theory and practice of international private law Research on the theory and practice of community correction Research on the practice and theory of tax law Research on the theory and practice of low carbon tourism Research on the theory and practice of military requirement work Research on the theory and practice of real estate development