Study on the harm and control of drug in Gansu province during the period of the republic of China 并列题名：Study on the harm and control of drug in Gansu province during the period of the republic of China Study on theory and practice of social insurance during the period of the republic of China 并列题名：Study on theory and practice of social insurance during the period of the republic of China Study on the revolution of urban road system in xi'an in the period of the republic of china Study on educational donation system during the period of the republic of China 并列题名：Study on the revolution of urban road system in xi'an in the period of the republic of china Merchants and merchant organizations in Jinan during the period of the Republic of China Research on the history of library in Beijing in the period of the Republic of China 并列题名：Study on educational donation system during the period of the republic of China