“30 Suspects Held in Death Syndicate”. The Philadelphia Enquirer. 11/4/1938. Page 2.
“Arsenic.” National Institute of Environmental Health Services (NIEHS). https://www.niehs.nih.gov/health/topics/agents/arsenic/index.cfm.
Blum, Deborah. The Poisoner’s Handbook: Murder and the Birth of Forensic Medicine in Jazz Age New York. New York: Penguin Books, 2010. Kindle Version.
Campbell, Colin J. “Poison in Ancient History: 5 Illustrative Examples of its Toxic Use.” The Collector. 1/9/2021. https://www.thecollector.com/poison-in-ancient-history-5-illustrative-examples-of-its-toxic-use.
“New Tests Reveal Arsenic in 2 Bodies”. The Philadelphia Inquirer. 12/14/1938. Page 2.
Gibbs, Frederick W. “Specific Form and Poisonous Properties: Understanding Poison in the fifteenth Century.” Preternature: Critical and Historical Studies on the Preternatural 2, n. 1 (2013), pp. 19-46.
Goad, Jim. “Witch’s Brew: How the ‘Philadelphia Poison Ring’ Exploited Unhappy Wives and Killed 100+ People.” Thought Catalog. 3/22/2021. https://thoughtcatalog.com/jim-goad/2019/12/witchs-brew-how-the-philadelphia-poison-ring-exploited-unhappy-wives-and-killed-100-people.
Helmenstine, Anne Marie. “6 Poisons that have been Used for Murder.” ThoughtCo. 6/28/2019. https://www.thoughtco.com/famous-poisoning-cases-4118225.
Parascandola, John. “Pharmacology and Folklore: The Arsenic Eaters of Styria.” American Institute of the History of Pharmacy. Vol 57, No. 1-2 (2015), pp. 3-16.
“Philadelphia Poison Ring.” Absolue Crime. http://www.absolutecrime.com/philadelphia-poison-ring.html.
“Poison Ring Suspect Held on 2d Charge”. The Philadelphia Inquirer. 11/5/1938. Page 15.
Snyder, Rachel. “Bewitched: Witchcraft, Life Insurance and the Business of Murder.” The Virginia Tech Undergraduate Historical Review 5, n. 1. Published 5/26/2017. https://vtuhr.org/articles/10.21061/vtuhr.v5i1.43.
The Arsenic Eaters of Styria. The Ultimate History Project. Accessed April 17, 2022. https://bit.ly/3JZzVuU.
“Toxicological Profile for Arsenic.” U.S. Department of Health and Human Services (HHS). August 2007. https://www.atsdr.cdc.gov/ToxProfiles/tp2.pdf.
Young, Robert James, Jr. “Arsenic and No Lace: The Bizarre Tale of a Philadelphia Murder Ring.” Pennsylvania History: A Journal of Mid-Atlantic Studies 67, n. 3 (Summer 2000): 397-414.