An unofficial anthology titled "In the Hunt: Unauthorized Essays on Supernatural" () was released on February 10, 2009, by Smart Pop and featured essays covering different aspects of both the series and its fanbase. "The Mythology of Supernatural: The Signs and Symbols Behind the Popular TV Show" (), published by Berkley Trade on August 2, 2011, sought to explore the religious and mythological roots of the show. And on October 1, 2011, ECW Press released the book "TV Goes to Hell: An Unofficial Road Map of Supernatural" () which explored topics such as folklore, religion, gender and sexuality, comedy, and music through essays from a number of contributors.