Words dropping, and a vendor missing
 

Words of quickening apparently doesn't drop at all, and is for the level 20 pet spell "Animate Dead" (currently buyable in paineel, and oggok)

Words of burnishing, however, drops off lower level mobs, and is for the level 44 spell "Dead man Floating"

There's also apparently a couple vendors missing in ak'anon, who are supposed to sell the level 24/29 spells