This Association is focused on researching and reviving historical fencing and fighting techniques. They offer free educational resources on a variety of martial art topics, including the history of sword duels.
The Triangle Sword Guild is a non-profit organization located in Triangle, North Carolina, dedicated to teaching modern students the ancient art of fencing. They focus on teaching the relatively new teachings of HEMA (Historical European Martial Arts). They do scholarly research on primary and secondary sources for European fighting, including duels.
Reliks Incorporated is a business that sells historical and fantastical sword reproductions. Their online library has a collection spanning from how to make historical swords, duels, how swords were used in different cultures, swords in the apocalypse, and historical weaponry and armor.