Bless Unleashed

Was going to do one for both collectible achievements, but I'm tired of staring/running over the same areas again and again to get them... someone else can do one for Journey Home (HMU if you have letter 15). One thing that I should note is that the locations that I am posting are not necessarily the only place you can find these collectibles. For instance I found Letter 6 in two spots, thought this was bugged and stopped looking for a while. But in speaking with a GM, there are multiple locations for some, but not all of the books.

Just to note, in some cases you may not see the book show immediately, particularly if you're racing to them or on an older Xbox, the same as other assets in the game. Hopping channels (Open Map, Click Left Stick) can help correct this. Holding X should still allow you to collect the book should it not become visible. They can also spawn under things they're supposed to be on top of. I've added links with images of each location after the description.

Letter 1: Talbor Tiamit's Musings - Races 1
This is located in South Sperios, Commercial District to the left of row of merchants that includes the Star Seed Vendor. It's on the bureau.
Location: https://imgur.com/VIxSQA1

Letter 2: Talbor Taimit's Musings - Races 2
This is located in Cazacor, Ordo University. When you go inside the university, it's toward the southwest corner of the building behind a column. This is likely the first one you will find. However, if you are doing this on a new character, Ordo University is instanced when you first arrive and you may not be able to interact with it yet.
Location: https://imgur.com/gVGCSxi

Letter 3: Talbor Taimit's Musings - Races 3
This is located in Navarra, Veteran's Club. When you enter this building, go to the second floor and you will see it there in the middle of the floor.
Location: https://imgur.com/PQZlBn9

Letter 4: Talbor Taimit's Musings - Races 4
This is located in Gnoll Wastes, Leafwind Village. This Shabiki village is along the road that leads to Tristezza, and you want to look to the right of a Shabiki named Chipo.
Location: https://imgur.com/sDo7u3s

Letter 5: Talbor Taimit's Musings - Military 1
This is located in Tristezza, Rosso's Castle. On the second floor of the castle in the back of the room, you'll find this on a dresser to your left.
Location: https://imgur.com/Nmwn0Lh

Letter 6: Talbor Taimit's Musings - Military 2
I have found this book in two places. You'll likely get this in Carzacor, Galloppa's Farm on top of a table near the teleporter. If you missed it there, you can also find this on top of a table in the Padana Ruins, Padana Village, right near the crafting stations.
Location 1: https://imgur.com/F0d16p2
Location 2: https://imgur.com/5bN6AiT

Letter 7: Talbor Taimit's Musings - Military 3
This is located in Kannus Mountains, Hive Cliffs. When you arrive in this area, along the first cluster of huts to the left in this Shabiki settlement you'll find this book on the table. It's right across from the teleporter.
Location: https://imgur.com/d5NXAMs

Letter 8: Talbor Taimit's Musings - Military 4
This is located in Kannus Valley, Skaa Refugee Camp and is somewhat easy to miss. When you arrive here there's a blacksmith forge in the back that you will have a side quest to get wood for. It's located to the right of it, on the ground.
Location: https://imgur.com/p6kIHmu

Letter 9: Talbor Taimit's Musings - Military 5
This is located in Timeless Jungle, Red Sun Dock on a desk in one of the buildings along the left side of the settlement.
Location: https://imgur.com/L0qcwV9

Letter 10: Talbor Taimit's Musings - Races 5
This is located in Zenkala, Linli Island. Off to the side opposite the teleporter here there's a stack of crates. The collectible should be on top of them.
Location: https://imgur.com/fYZDLcL

And there you have it. If you've found other books elsewhere, let me know and I can add them to this list.

Enjoy!

Here is a Video guide by youtube user LV 1 Blue Slime that will help you locate the pages for both Anonymous Odyssey and Encyclopedia Historia achievements. ( obtuse language's guide is good its just that i know some people prefur video guides