https://www.youtube.com/watch?v=-1oQLPRE21o&feature=youtu.be
https://genius.com/Zodiac-killer-school-children-make-nice-targets-7th-zodiac-letter-annotated
https://edition.cnn.com/2020/12/11/us/zodiac-killer-cypher-340-code-trnd/index.html
https://www.reddit.com/r/UnresolvedMysteries/comments/kb8v2h/fbi_confirms_that_the_zodiac_killers_340_cypher/
https://www.history.com/news/the-zodiac-ciphers-what-we-know
https://en.wikipedia.org/wiki/Zodiac_Killer
https://www.zodiackiller.com/FerrinMageau.html
https://www.zodiacciphers.com/complete-408-cipher.html
https://zodiackiller.fandom.com/wiki/Donald_Harden
https://www.zodiacciphers.com/bus-bomb-letter.html
http://practicalcryptography.com/ciphers/homophonic-substitution-cipher/
https://www.zodiackiller.com/ShepardHartnell.html