Rise of the Tomb Raider: Documents, Siberian Wilderness secrets, tips, location Rise of the Tomb Raider guide, walkthrough
Document 1

At the corpse inside the cave. You find it while searching for toadstools that you need for crafting poison arrows.
Document 2

On your way to the cave with the bear. It is on the table surrounded by two soldiers, in the area enclosed within a low wall.
Document 3

On the ground, in the cave where a bear lurked. After the bear is done, approach the stag's remains.
Document 4

Close to the camp on a ledge.
Document 5

Just like the previous one, close to the camp, at the wall close to the road.
Document 6

On the ledge. You get there after you climb onto the branch of the nearby tree and take a leap from there.