See: “The Two Worlds” advertisement, 1931
Advertisement for “Light: A Weekly Journal of Psychical, Occult, & Mystical Research. Edited by E. Dawson Rogers,” pamphlet, “Mysteries of Mediumship. A Spirit Interviewed: Being an Account of the Life and Mediumship of J. J. Morse,” reprinted from “Light,” 1894, Folder “Mediumship,” Box 30, Eileen J. Garrett Parapsychology Foundation Collection, Collection 331, Special Collections, University of Maryland, Baltimore County (Baltimore, MD).