If I recall correctly, one of my PCs found them at the spots shown in your screenshot after he entered the delve, killed the boss, exited, and started climbing the steps to the top. As far as I know, they were not shown by Lorebooks as available through a quest, whether any of them might have been inside the delve (originally). If you don't find them, then please read, and post to, the following on-going discussion:santialonso wrote: »In Torinaan, Auridon. Must be the next notes:
- The Gifts of Magnus.
- The Fires of Truth.
- Letter to an Aldarch.
However, I go to the spot, the area is bright, but I can not take them.
(screenshot image deleted from quote by Shadowshire)