1. “All Hell Breaks Loose (Part 1).” Supernatural, season 2, episode 21, aired May 10, 2007, on The WB/The CW.
2. “Back and to the Future.” Supernatural, season 15, episode 1, aired October 10, 2019, on The WB/The CW.
3. Berthin, Christine. Gothic Hauntings: Melancholy Crypts and Textual Ghosts. London and New York: Palgrave, 2010.
4. “Bloody Mary.” Supernatural, season 1, episode 5, aired October 11, 2005, on The WB/The CW.
5. “Carry On.” Supernatural, season 15, episode 20, aired November 19, 2020, on The WB/The CW.