Prominent UFO researcher John Keel concurred. After surveying the literature on [[demonology]] Keel declared:<ref name=Gleghorn/>{{Cquote|The manifestations and occurrences described in this imposing literature are similar if not entirely identical to the UFO phenomenon itself.}} | Prominent UFO researcher John Keel concurred. After surveying the literature on [[demonology]] Keel declared:<ref name=Gleghorn/>{{Cquote|The manifestations and occurrences described in this imposing literature are similar if not entirely identical to the UFO phenomenon itself.}} |