I have a lot of books on things "unexplained", and unfortunately most of them have little if any scholarship behind them, usually accepting outlandish claims at face value. These are not like that. These are good in that they at least try to offer a variety of potential explanations, and as often as not state that a hoax is indeed most likely. While I wouldn't say these are scholarly, they are good stuff if you want inspiration for stories, without the aftertaste of naivete so many other works in the genre leave you with. ( )