Collections of preface and postscript to different editions of Dufu's works in Qing dynasty 并列题名：Collections of preface and postscript to different editions of Dufu's works in Qing dynasty Extractions of the prefaces and postscripts from books of songs in Qing Dynasty 并列题名：Extractions of the prefaces and postscripts from books of songs in Qing Dynasty Research on preface and postscript of novels in Qing dynasty 并列题名：Research on preface and postscript of novels in Qing dynasty