又根据诗题、自注、文本、交游、史书、笔记、方志等文献材料考索出袁凯相当一部分作品的写作年限和年代。
The writing years and periods of part of Yuan Kai ' works are also found out on the basis of such documents as the poetic titles , annotations , texts , travels , historical records , notes and local annals .
袁凯