Amnesia: The Bunker

Here are the notes in the same order as they appear in the game menu. You can use this to look up any you are missing. The last few that I didn't find organically and had to look up are marked with [**] and they were all in the soldier's barracks - either hiding in the lockers, wardrobes and one was on a top bunk.

This popped for me on my second play-through and I didn't have all the notes in my possession on this file (i.e. I had 50/52 notes) and the achievement popped. The two I didn't have, I think I picked up on my first run through.

As of June 2023, this game is buggy for popping achievements. Many of us do not have the final achievement for unlocking the 51 other achievements. This one is also buggy for people. Best guidance is to collect all the notes in one save in a single session. Good luck..!

Different soldier based on the key location:
> I Have the Communications Key

Dr. Josinski
> Rats and Burnt Corpses
> Amnesia Cause
> Autopsy of Reynard

Henri Clement (me)
> Clement's Journal - Routine Patrol
> Clement's Journal - Agony
> Clement's Journal - No Word
> Clement's Journal - Compelled

Q. Friloux
> Note from Head Clerk re Dog Tags

Sdt. Boisrond
> Fuel and Fire
> Wrench Location Note
> How to Get the Hell Out of Here

Unknown Author
> Keep the Light on!

Sgt. Stephane Joubert
> Roman Tunnel Update
> Comment on Noyer's Report
> Joubert's Journal - Patrol Debriefing
> Joubert's Journal - Strange Sounds
> Joubert's Final Journal

Major Sergeant Delpy
> Toussaint's Fate
> Prisoner in Custody

Sdt. LaRue
> LaRue's Report

Sdt. Chanard
> The Rats
> Fear and Paranoia
> I Saw Its Face
> It Can Hear Me

Foreman Stafford
> Note to a Dead Friend
> Where's the Pillbox key?
> Daisy-Chained Switches

Sgt. Reynard
> Noyer's Translations
> List of the Guilty
> Permission to Court Martial
> Update on Prisoner

M. Fournier
> Increased Security on Arsenal
> Assumptions About Motive
> Where's our Wine
> Reynard is Dead
> Shooting the Beast

Farber
> Gathering of the Willing
> Farber's Last Note **

Sdt. Marceau
> The Officers have Fled

Alex Noyer
> Noyer's Journal - Part 1
> Noyer's Journal - Part 2

Ozanne
> Note to Farber

Tremblay
> Farber Dies

Toussaint Beaufoy
> We Whirl the World **
> Toussaint's Journal
> Toussaint's Madness

Augustin Lambert
> Lambert's Journal - Part 1
> Lambert's Journal - Part 2

Major Blanchet
> In Charge of Security

J. Renoir
> About Digging too Deep

Johannes Nicolay
> Nicolay's Unsent Letter **

This Guide is to help all people who needs to get other Achievements on the list. Which is Collectibles, Missables Achievements that you can gather on your playthrough and yes the Achievement is still glitched today. So for the few who says that, I do know that the Developers did say something in the steam forms. So it might get patched in the future or not. As they did say that it's not showing up glitched in their systems.

here is my solution hope it could help some :)
1) Start a game
2) Do not collect any notes
3) Advance in the game (unlock paths, unlock lockers, unlock drawers, etc...)
4) Save
5) Now collect all 52 notes at once without saving in case the game crashes
In any case I got it like that since in my first part I also had the 52 notes but without success