https://www.newsweek.com/2014/08/15/look-behind-plot-kill-hitler-263200.html
https://time.com/5629999/operation-valkyrie-july-plot/

https://allthatsinteresting.com/adolf-hitler-assassination-attempts

https://historycollection.co/18-of-the-many-attempts-to-assassinate-adolf-hitler-by-the-german-resistance/

https://www.totallytimelines.com/adolf-hitler-assassination-attempts-1921-1945/

https://web.archive.org/web/20150407163855/http://josephkaminski.net/2015/02/16/the-plots-to-kill-hitler/

https://www.spectator.co.uk/2018/12/why-didnt-they-try-harder-to-assassinate-hitler/

https://www.history.com/topics/world-war-ii/july-plot

https://www.telegraph.co.uk/culture/books/bookreviews/4527748/Valkyrie-the-Plot-to-Kill-Hitler-by-Philipp-von-Boeselager-review.html