Study on the folk characters in contract documents since Song and Yuan dynasties 并列题名：Study on the folk characters in contract documents since Song and Yuan dynasties Study on female articles in the poems of tang and song dynasties Study on the group of Xin'an doctors in Ming and Qing Dynasties Study on the opera troupe of family in Ming and Qing dynasties Study on the satirical fiction in the Ming and Qing dynasties Study on the induction thought of Confucianism in Song and Ming dynasties a study on the legal system of foreign trade during the ming and qing dynasties