The International Association for the Preservation of Spiritualist and Occult Periodicals (IAPSOP) is a US‑based private organization focused on the digital preservation of Spiritualist and occult periodicals and monographs (our Standard Spiritualist and Occult Corpus, or SSOC) published between the Congress of Vienna and the start of the Second World War.

Our all‑volunteer staff digitizes, indexes, and makes available free of charge these periodicals for use by students and researchers. We have a standing want list and will respond promptly to inquiries and offers from sellers. We accept contributions of material and labor to further this work.