Nazi Saboteurs: Hitler's Secret Attack on America by Samantha Seiple
Saboteurs: The Nazi Raid on America by Michael Dobbs
https://muse.jhu.edu/article/744176#:~:text=On%20June%2013th%2C%201942%2C%20eight,by%20one%20of%20their%20own.
https://historynewsnetwork.org/article/32084
https://www.natgeotv.com/me/hitlers-secret-attack-on-america
https://www.warhistoryonline.com/war-articles/hitler-planned-bomb-manhattan-skyscrapers.html
https://www.britannica.com/event/Pearl-Harbor-attack
https://www.fbi.gov/history/famous-cases/nazi-saboteurs-and-george-dasch
https://encyclopedia.ushmm.org/content/en/article/german-american-bund
https://en.wikipedia.org/wiki/William_G._Sebold
https://en.wikipedia.org/wiki/Edward_Kerling