I believe the book telling about the Amulets is titled: "Dusty Tomb".
And for those people who read all books ... there is another book (I don't remember the name of that book, but you find it in a dungeon, I think in "Lost Cave") writing about "Slantwig" and if you patiently enough to search and think about it you can find also the Amulet of Slantwig" by using another Amulet on a certain place in the Lost Cave
Funny thing now is: playing before Ego Draconis and now playing the DKS I don't find the fourth orange "lever"

.... but I know it let appear a treasure chest somewhere ...
between Sosostra and the New Miner's Dig