- http://holmesmurdercastle.wordpress.com/
- http://www.biography.com/people/h-h-holmes-307622
- http://www.prairieghosts.com/holmes.html
- http://www.randomhouse.com/crown/devilinthewhitecity/holmes.html
- http://www.straightdope.com/columns/read/620/did-dr-henry-holmes-kill-200-people-at-a-bizarre-castle-in-1890s-chicago
- http://www.trutv.com/library/crime/serial_killers/history/holmes/20.html