Theoretical and empirical study of family farm development theoretical and empirical study of the Pearl River Delta region Theoretical and empirical study of teachers' sense of gain theoretical and empirical study based on Chinese market a theoretical and empirical study of food safety regulation in China Theoretical and empirical study on cyclical company valuation Theoretical and empirical study on the power list system 并列题名:Theoretical and empirical study of teachers' sense of gain theoretical and empirical analysis for China theoretical and empirical studies