https://en.wikipedia.org/wiki/William_McKinley
https://www.history.com/this-day-in-history/president-william-mckinley-is-shot#:~:text=Czolgosz%2C%20a%20Polish%20immigrant%2C%20grew,thought%20was%20a%20corrupt%20government.
https://www.theregister.com/2006/10/20/the_odd_body_electrocution/
https://en.wikipedia.org/wiki/Leon_Czolgosz
https://www.snopes.com/fact-check/taste-buds/
https://books.google.com.ph/books?id=Q2fhPjTJutgC&q=ink&redir_esc=y#v=snippet&q=ink&f=false
https://www.whitehouse.gov/get-involved/write-or-call/#:~:text=Call%20the%20President&text=If%20possible%2C%20email%20us!,11%20inch%20sheet%20of%20paper.&text=Please%20include%20your%20return%20address,as%20well%20as%20your%20envelope.
https://www.popularmechanics.com/technology/news/a13875/secret-service-ink-forensics-library/
https://nypost.com/2019/07/08/inside-the-secret-service-lab-with-more-than-15k-ink-samples/
https://www.usatoday.com/story/news/2018/10/03/poisoned-letters-sent-white-house-had-ricin-element-arrest-made/1516061002/
https://www.bbc.com/news/world-us-canada-54221893
https://www.usatoday.com/story/news/politics/onpolitics/2017/08/24/secret-service-spent-7-100-renting-luxury-portable-toilets-trumps-bedminster-trip/598649001/
https://www.forbes.com/sites/danielasirtori/2017/03/20/uruguay-high-priced-protection/?sh=60e0667c2f7d
https://www.usatoday.com/story/news/politics/onpolitics/2017/08/24/secret-service-spent-7-100-renting-luxury-portable-toilets-trumps-bedminster-trip/598649001/
https://people.howstuffworks.com/why-does-the-secret-service-protect-a-presidents-adult-children.htm
https://www.cbsnews.com/news/bush-daughters-kept-secret-service-protection/
https://www.ksat.com/news/local/2020/11/10/three-people-ages-18-20-arrested-after-throwing-eggs-insults-at-trump-prayer-group-police-say/
https://en.wikipedia.org/wiki/Secret_Service_code_name
https://www.history.com/news/presidential-affairs-jfk-lbj-fdr-harding-clinton-trump
https://tribunecontentagency.com/tns_articles/when-jimmy-carters-white-house-was-a-tour-stop-for-long-haired-torpedo-smoking-rock-outlaws/
https://www.washingtonian.com/2013/03/25/secret-service-prostitution-scandal-one-year-later/