The Corbitt Diaries
The diaries describe Corbitt’s various occult experiments, including the summoning of some unearthly spirit and other magic, and clearly describe a spell entitled “Call Forth the Opener of Ways”
Liber Ivornis
Latin, translation to english commisioned by the Investigators.
The Cult of Ghouls
English (translation of Cultes Des Goules), by Joseph Curwen.