The Last Case of Benedict Fox: Definitive Edition

There are 8 pages which you can review within your inventory to confirm which you're missing. They should be found around the main path, but sometimes are a platform removed and thus easily missed. You can go back anytime as far as I've found.

1. Conundrum Keys' Note
2. Note With Symbols
3. Conundrum Symbols Note
4. Conundrum Note
5. Golem Revival Ritual Note
6. Piano Page
7. Secret Behind The Statue
8. Secret Door Page

Check out this video if you missed one (video credit to the channel):

A really helpful tip is if you look on the map you will notice certain areas of the Map are highlighted in red. That usually indicates that there is either Ink to collect or items to find. That's how I found the last Conundrum Key Note.