Here is something for the fans of "The Ritual": „Begone Satan! A Soul Stirring Account of Diabolical Possession in Iowa – After 23 Day’s Battle in December 1928, Devil Was Forced to Leave“, which is a basis for the film, is available for free in digitalized form at the Internet Archive and it has 52 pages. Don't be surprised, it wasn't written by Father Joseph Steiger and also no by Rev. Theophilus Riesinger, but of course they are mentioned in it and there are also photos of them.
You can find it here: https://archive.org/details/begonesatansouls00vogl_0/page/6/mode/2up














