If the occult or the supernatural is common enough that organisations arise to deal with it, whether these by private or governmental in nature, then such organisations will probably produce training material, perhaps of variable quality, to help recruits and people deal with supernatural encounters.
This is a collection of 100 such items intended for a modern setting, but transferable to others. Each is the title of a pamphlet, seminar or other training material (some with cheesy titles, as might actually be the case) that could be found or used in such a situation. Whether or not this material has a game benefit is up to the GameMaster - it could be flawed - but a small benefit in a relevant situation could be applied.
Here is a sample result:
Not Your Fantasy Elf: The Truth Behind the Modern Depiction - The original origins of elves, from the Celtic Sidhe and the Norse Ælf, and how modern depictions differ from these
One page of the supplement is the cover, one page the front matter and introduction.