I found this technique for taking notes inside of books from @nntaleb on Twitter.

Create a content index at the start of the book with references to the page and point of interest. This makes retrieval of details trivial because the associated notes live in the same location as the information [1].

If you already take notes in the margins of books consider adding this technique too to further index your margin comments and make retrieval easier.

Figure 1: An example of indexed note taking from @nntaleb’s tweet.

Footnotes

[1] See The Code Proximity Conjecture.