Actually we have Milton's commonplace book, his reading notes, and you can find it all in English translation in volume one of The Complete Prose Works of John Milton.

事实上我们有弥尔顿的那本普通的书，他的阅读笔记，你们可以找到完全的英译本,在弥尔顿全部散文作品的第一卷。

耶鲁公开课 - 弥尔顿课程节选