Briggs, C. V. (2010). Encyclopedia of the unseen world: The ultimate guide to apparitions, death bed visions, mediums, shadow people, wandering spirits, and much, much more (1. publ.). Weiser.

Briggs, Constance Victoria. Encyclopedia of the Unseen World: The Ultimate Guide to Apparitions, Death Bed Visions, Mediums, Shadow People, Wandering Spirits, and Much, Much More. 1. publ. San Francisco, Cal.: Weiser, 2010.

Briggs, Constance Victoria. Encyclopedia of the Unseen World: The Ultimate Guide to Apparitions, Death Bed Visions, Mediums, Shadow People, Wandering Spirits, and Much, Much More. 1. publ. Weiser, 2010.