Pages 1, 8, 11, & 12 can be found on the Searing Flameworms in Malenhad. It took me about 2-3 hours to farm these solo.
The remaining pages were found on the orcs (skirmish or warrior) in Eastern Malenhad on the other side of the "wall." This "wall" is a bunch of statues lined up that cause serious dread when near and may not be crossed until you have completed Book 6 Chapter 6. Otherwise you will die of "misadventure" for trying to cross it. Once you are able to cross the wall and start farming the last four pages be sure to stay in "Eastern Malenhad." Watch the area indicator under the mini-map. Failure to do so will result in hours lost fighting the same mobs and watching the Burglar in your party get their pages and you get none. Once we realized where we actually were we moved back to the right area and all four of my pages dropped within 30 minutes. I don't count it as a true loss of time since the Burglar, who is in my kinship, was able to get his completed and he got level 45 in the process so he was able to equip the trait after visiting a Bard.